314 results on '"Aiyi Liu"'
Search Results
2. Prospective relations of maternal reward-related eating, pregnancy ultra-processed food intake and weight indicators, and feeding mode with infant appetitive traits
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Jenna R. Cummings, Myles S. Faith, Leah M. Lipsky, Aiyi Liu, Jan T. Mooney, and Tonja R. Nansel
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Infant Appetitive Traits ,Pregnancy ,Reward-Related Eating ,Diet ,Weight ,Breastfeeding ,Nutritional diseases. Deficiency diseases ,RC620-627 ,Public aspects of medicine ,RA1-1270 - Abstract
Abstract Background Infant appetitive traits including eating rate, satiety responsiveness, food responsiveness, and enjoyment of food predict weight gain in infancy and early childhood. Although studies show a strong genetic influence on infant appetitive traits, the association of parent and infant appetite is understudied. Furthermore, little research examines the influence of maternal pregnancy dietary intake, weight indicators, and feeding mode on infant appetite. The present study investigated relations of maternal reward-related eating, pregnancy ultra-processed food intake and weight indicators, and feeding mode with infant appetitive traits. Methods Mothers in the Pregnancy Eating Attributes Study (458 mothers enrolled, 367 retained through delivery) completed self-report measures of reward-related eating, and principal component analysis yielded two components: (1) food preoccupation and responsiveness and (2) reinforcing value of food. Mothers completed 24-h dietary recalls across pregnancy, and the standardized NOVA (not an acronym) system categorized recalled foods based on processing level. Maternal anthropometrics were measured across pregnancy. At infant age 6 months, mothers reported on feeding mode and infant appetitive traits. Linear regressions were conducted predicting infant appetitive traits from household income-poverty ratio (step 1); maternal reward-related eating components (step 2); pregnancy ultra-processed food intake (% of energy intake), early pregnancy body mass index, and gestational weight gain (step 3); and exclusive breastfeeding duration (step 4). Results A 1-SD greater maternal food preoccupation and responsiveness was associated with 0.20-SD greater infant satiety responsiveness (p = .005). A 1-SD greater % energy intake from ultra-processed foods during pregnancy was associated with 0.16-SD lower infant satiety responsiveness (p = .031). A 1-SD longer exclusive breastfeeding duration was associated with 0.18-SD less infant food responsiveness (p = .014). Other associations of maternal reward-related eating, pregnancy ultra-processed food intake and weight indicators, and feeding mode with infant appetitive traits were non-significant. Conclusions Proximal early-life environmental factors including maternal pregnancy dietary intake and feeding mode may facilitate or protect against obesogenic infant appetitive traits, whereas infant appetite may not parallel maternal reward-related eating. Further investigation into the etiology of appetitive traits early in development, particularly during solid food introduction, may elucidate additional modifiable risk factors for child obesity. Trial registration Clinicaltrials.gov. Registration ID – NCT02217462 . Date of registration – August 13, 2014.
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- 2022
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3. Associations of ultra-processed food intake with maternal weight change and cardiometabolic health and infant growth
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Jenna R. Cummings, Leah M. Lipsky, Carolina Schwedhelm, Aiyi Liu, and Tonja R. Nansel
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Ultra-processed food ,Pregnancy ,Postpartum ,Maternal weight change ,Cardiometabolic health ,Infant weight-for-length ,Nutritional diseases. Deficiency diseases ,RC620-627 ,Public aspects of medicine ,RA1-1270 - Abstract
Abstract Background Excessive intake of ultra-processed foods, formulated from substances extracted from foods or derived from food constituents, may be a modifiable behavioral risk factor for adverse maternal and infant health outcomes. Prior work has predominately examined health correlates of maternal ultra-processed food intake in populations with substantially lower ultra-processed food intake compared to the US population. This longitudinal study investigated relations of ultra-processed food intake with maternal weight change and cardiometabolic health and infant growth in a US cohort. Methods Mothers in the Pregnancy Eating Attributes Study were enrolled at ≤12 weeks gestation and completed multiple 24-Hour Dietary Recalls within six visit windows through one-year postpartum (458 mothers enrolled, 321 retained at one-year postpartum). The NOVA (not an acronym) system categorized food and underlying ingredient codes based on processing level. Maternal anthropometrics were measured throughout pregnancy and postpartum, and infant anthropometrics were measured at birth and ages 2 months, 6 months, and 1 year. Maternal cardiometabolic markers were analyzed from blood samples obtained during the second and third trimesters. Results Holding covariates and total energy intake constant, a 1-SD greater percent energy intake from ultra-processed foods during pregnancy was associated with 31% higher odds of excessive gestational weight gain (p = .045, 95% CI [1.01, 1.70]), 0.68±0.29 mg/L higher c-reactive protein during pregnancy (p = .021, 95% CI [0.10, 1.26]), 6.7±3.4% greater gestational weight gain retained (p = .049, 95% CI [0.03, 13.30]), and 1.09±0.36 kg greater postpartum weight retention (p = .003, 95% CI [0.38, 1.80]). No other significant associations emerged. Conclusions Ultra-processed food intake during pregnancy may be a modifiable behavioral risk factor for adverse maternal weight outcomes and inflammation. Randomized controlled trials are needed to test whether targeting ultra-processed food intake during pregnancy may support optimal maternal health. Trial registration Clinicaltrials.gov. Registration ID – NCT02217462 . Date of registration – August 13, 2014.
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- 2022
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4. Using food network analysis to understand meal patterns in pregnant women with high and low diet quality
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Carolina Schwedhelm, Leah M. Lipsky, Grace E. Shearrer, Grace M. Betts, Aiyi Liu, Khalid Iqbal, Myles S. Faith, and Tonja R. Nansel
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Meals ,Breakfast ,Lunch ,Dinner ,Snacks ,Network analysis ,Nutritional diseases. Deficiency diseases ,RC620-627 ,Public aspects of medicine ,RA1-1270 - Abstract
Abstract Background Little is known about how meal-specific food intake contributes to overall diet quality during pregnancy, which is related to numerous maternal and child health outcomes. Food networks are probabilistic graphs using partial correlations to identify relationships among food groups in dietary intake data, and can be analyzed at the meal level. This study investigated food networks across meals in pregnant women and explored differences by overall diet quality classification. Methods Women were asked to complete three 24-h dietary recalls throughout pregnancy (n = 365) within a prospective cohort study in the US. Pregnancy diet quality was evaluated using the Healthy Eating Index-2015 (HEI, range 0-100), calculated across pregnancy. Networks from 40 food groups were derived for women in the highest and lowest HEI tertiles at each participant-labeled meal (i.e., breakfast, lunch, dinner, snacks) using Gaussian graphical models. Network composition was qualitatively compared across meals and between HEI tertiles. Results In both HEI tertiles, breakfast food combinations comprised ready-to-eat cereals with milk, quick breads with sweets (e.g., pancakes with syrup), and bread with cheese and meat. Vegetables were consumed at breakfast among women in the high HEI tertile only. Combinations at lunch and dinner were more varied, including vegetables with oils (e.g., salads) in the high tertile and sugary foods with nuts, fruits, and milk in the low tertile at lunch; and cooked grains with fats (e.g., pasta with oil) in the high tertile and potatoes with vegetables and meat in the low tertile at dinner. Fried potatoes, sugar-sweetened beverages, and sandwiches were consumed together at all main meals in the low tertile only. Foods were consumed individually at snacks in both tertiles; the most commonly consumed food were fruits in the high HEI tertile and cakes & cookies in the low tertile. Conclusions In this cohort of pregnant women, food network analysis indicated that food combinations differed by meal and between HEI tertiles. Meal-specific patterns that differed between diet quality tertiles suggest potential targets to improve food choices at meals; the impact of meal-based dietary modifications on intake of correlated foods and on overall diet quality should be investigated in simulations and intervention studies. Trial registration PEAS was registered with number NCT02217462 in Clinicaltrials.gov on August 13, 2014.
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- 2021
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5. Group testing can improve the cost-efficiency of prospective-retrospective biomarker studies
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Wei Zhang, Zhiwei Zhang, Julia Krushkal, and Aiyi Liu
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Biomarker study design ,Cost-efficiency ,Group testing ,Pooling ,Two-phase sampling ,Medicine (General) ,R5-920 - Abstract
Abstract Background Cancer treatment is increasingly dependent on biomarkers for prognostication and treatment selection. Potential biomarkers are frequently evaluated in prospective-retrospective studies in which biomarkers are measured retrospectively on archived specimens after completion of prospective clinical trials. In light of the high costs of some assays, random sampling designs have been proposed that measure biomarkers for a random sub-sample of subjects selected on the basis of observed outcome and possibly other variables. Compared with a standard design that measures biomarkers on all subjects, a random sampling design can be cost-efficient in the sense of reducing the cost of the study substantially while achieving a reasonable level of precision. Methods For a biomarker that indicates the presence of some molecular alteration (e.g., mutation in a gene), we explore the use of a group testing strategy, which involves physically pooling specimens across subjects and assaying pooled samples for the presence of the molecular alteration of interest, for further improvement in cost-efficiency beyond random sampling. We propose simple and general approaches to estimating the prognostic and predictive values of biomarkers with group testing, and conduct simulation studies to validate the proposed estimation procedures and to assess the cost-efficiency of the group testing design in comparison to the standard and random sampling designs. Results Simulation results show that the proposed estimation procedures perform well in realistic settings and that a group testing design can have considerably higher cost-efficiency than a random sampling design. Conclusions Group testing can be used to improve the cost-efficiency of biomarker studies.
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- 2021
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6. Differential reporting of fruit and vegetable intake among youth in a randomized controlled trial of a behavioral nutrition intervention
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Namrata Sanjeevi, Leah Lipsky, Aiyi Liu, and Tonja Nansel
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Differential reporting bias ,Carotenoids ,Fruit and vegetable intake ,Randomized controlled trial ,Type 1 diabetes ,Nutritional diseases. Deficiency diseases ,RC620-627 ,Public aspects of medicine ,RA1-1270 - Abstract
Abstract Background Nutrition interventions typically rely on self-reported intake that may be susceptible to differential reporting bias due to exposure to the intervention. Such differences may result from increased social desirability, increased attention to eating or improved recall accuracy, and may bias estimates of the intervention effect. This study investigated differential reporting bias of fruit and vegetable intake in youth with type 1 diabetes participating in a randomized controlled trial targeting increased whole plant food intake. Methods Participants (treatment n = 66, control n = 70) completed 3-day food records at baseline, 6-,12-, and 18-months, from which fruit and vegetable intake (servings/day) was calculated. Serum carotenoids were assessed at these visits using a high-performance liquid chromatography-based assay. Linear regression estimated associations of fruit and vegetable intake with serum carotenoids by treatment assignment. Multiplicative interaction terms tested the interaction of treatment assignment with fruit and vegetable intake on serum carotenoids for each visit and within each group over time. Results The association of fruit and vegetable intake with serum carotenoids was significantly lower in the control versus intervention group at baseline (β = 0.22 Vs 0.46) and 6-month visits (β = 0.37 Vs 0.54), as evidenced by significant interaction effects. However, the association of fruit and vegetable intake with serum carotenoids did not significantly differ over time for either group. Conclusions While the stronger association of fruit and vegetable with carotenoids in the treatment arm suggests greater reporting accuracy, this difference was evident at baseline, and did not change significantly over time in either group. Thus, results indicate greater subject-specific bias in the control arm compared to the treatment, and lack of evidence for reactivity to the intervention by treatment assignment. Clinical trial registry number and website NCT00999375
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- 2019
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7. The effect of remuneration schedule on data completion and retention in the pregnancy eating attributes study (PEAS).
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Ndeah Terry, Leah M Lipsky, Anna Maria Siega-Riz, Aiyi Liu, and Tonja R Nansel
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Medicine ,Science - Abstract
Maximizing data completion and study retention is essential in population research. This study examined the effect of remuneration schedule and data collection modality on data completion and retention in the Pregnancy Eating Attributes Study cohort. Participants (n = 458) completed online surveys and attended six in-person study visits. Initially, remuneration was a prespecified amount per visit, then was changed mid-study to be prorated based on the number of forms completed. Additionally, survey data collection modality was changed to in-person at the sixth study visit. In this secondary data analysis, there was no effect of remuneration schedule on withdrawal rates or time-to-withdrawal. Survey completion was significantly lower under prorated remuneration at the first visit but did not significantly differ at subsequent visits. The lump sum group had significantly greater odds of completely the first and second trimester dietary record (OR = 4.1, OR = 2.6, respectively) then the prorated group but were almost half as likely to complete the dietary record at the 6-month postpartum visit (OR = 0.5). Survey completion at sixth visit was significantly higher for in-person versus online completion (68.6% vs. 93.1%). Findings suggest that remuneration schedule and data collection modality can impact completion of self- reported assessments.
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- 2021
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8. Self-compassion and posttraumatic growth mediate the relations between social support, prosocial behavior, and antisocial behavior among adolescents after the Ya’an earthquake
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Aiyi Liu, Wenchao Wang, and Xinchun Wu
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social support ,self-compassion ,ptg ,antisocial behaviour ,prosocial behaviour ,Psychiatry ,RC435-571 - Abstract
Background: Previous studies indicate that social support, self-compassion, and posttraumatic growth (PTG) can affect prosocial behaviour and antisocial behaviour, but few studies have examined their combined role in prosocial and antisocial behaviour among adolescents who have experienced traumatic events. Objective: This study examined the mediating roles of self-compassion and PTG in the relationship between social support and prosocial and antisocial behaviour among Chinese adolescents after the Ya’an earthquake. Method: Four and a half years after the Ya’an earthquake, 492 students aged 13 to 18 in Lushan County (98.6% of the 499 students surveyed) were assessed using the following system: Measures of Trauma Exposure Questionnaire, Social Support Questionnaire, Self-Compassion Scale, Posttraumatic Growth Inventory, and Child Behaviour Problems Questionnaire. Results: When we controlled for gender, age, and traumatic exposure, social support had a positive effect on prosocial behaviour. Moreover, social support had an indirect and positive effect on prosocial behaviour via positive self-compassion and PTG, as well as via an indirect path from positive self-compassion to PTG, but social support had a negative effect on antisocial behaviour via PTG, as well as via an indirect path from positive self-compassion to PTG on antisocial behaviour. Social support also had a positive effect on antisocial behaviour via negative self-compassion. Conclusion: Findings suggest that increased support may be beneficial for prosocial behaviour and reduce antisocial behaviour. Self-compassion and PTG play a significant mediating role between social support, prosocial behaviour, and antisocial behaviour.
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- 2021
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9. Exosomal Carboxypeptidase E (CPE) and CPE-shRNA-Loaded Exosomes Regulate Metastatic Phenotype of Tumor Cells
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Sangeetha Hareendran, Bassam Albraidy, Xuyu Yang, Aiyi Liu, Anne Breggia, Clark C. Chen, and Y. Peng Loh
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cancer proliferation ,hepatocellular carcinoma ,metastasis ,engineered exosomes ,diagnostic biomarker ,cancer therapy ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Background: Exosomes promote tumor growth and metastasis through intercellular communication, although the mechanism remains elusive. Carboxypeptidase E (CPE) supports the progression of different cancers, including hepatocellular carcinoma (HCC). Here, we investigated whether CPE is the bioactive cargo within exosomes, and whether it contributes to tumorigenesis, using HCC cell lines as a cancer model. Methods: Exosomes were isolated from supernatant media of cancer cells, or human sera. mRNA and protein expression were analyzed using PCR and Western blot. Low-metastatic HCC97L cells were incubated with exosomes derived from high-metastatic HCC97H cells. In other experiments, HCC97H cells were incubated with CPE-shRNA-loaded exosomes. Cell proliferation and invasion were assessed using MTT, colony formation, and matrigel invasion assays. Results: Exosomes released from cancer cells contain CPE mRNA and protein. CPE mRNA levels are enriched in exosomes secreted from high- versus low-metastastic cells, across various cancer types. In a pilot study, significantly higher CPE copy numbers were found in serum exosomes from cancer patients compared to healthy subjects. HCC97L cells, treated with exosomes derived from HCC97H cells, displayed enhanced proliferation and invasion; however, exosomes from HCC97H cells pre-treated with CPE-shRNA failed to promote proliferation. When HEK293T exosomes loaded with CPE-shRNA were incubated with HCC97H cells, the expression of CPE, Cyclin D1, a cell-cycle regulatory protein and c-myc, a proto-oncogene, were suppressed, resulting in the diminished proliferation of HCC97H cells. Conclusions: We identified CPE as an exosomal bioactive molecule driving the growth and invasion of low-metastatic HCC cells. CPE-shRNA loaded exosomes can inhibit malignant tumor cell proliferation via Cyclin D1 and c-MYC suppression. Thus, CPE is a key player in the exosome transmission of tumorigenesis, and the exosome-based delivery of CPE-shRNA offers a potential treatment for tumor progression. Notably, measuring CPE transcript levels in serum exosomes from cancer patients could have potential liquid biopsy applications.
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- 2022
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10. Cumulative Lactation and Clinical Metabolic Outcomes at Mid-Life among Women with a History of Gestational Diabetes
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Pandora L. Wander, Stefanie N. Hinkle, Daniel A. Enquobahrie, Jing Wu, Sylvia H. Ley, Louise G. Grunnet, Jorge E. Chavarro, Mengying Li, Anne A. Bjerregaard, Aiyi Liu, Peter Damm, Seth Sherman, Shristi Rawal, Yeyi Zhu, Liwei Chen, James L. Mills, Frank B. Hu, Allan Vaag, Sjurdur F. Olsen, and Cuilin Zhang
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lactation ,breastfeeding ,pregnancy ,women ,diabetes ,obesity ,Nutrition. Foods and food supply ,TX341-641 - Abstract
Lactation is associated with a lower risk of subsequent cardiometabolic disease among parous women; however, the underlying mechanisms are unknown. Further, the potential protective effects of lactation on cardiometabolic risk markers at mid-life among high-risk women with past gestational diabetes (GDM) are not established. Using data from the Diabetes & Women’s Health Study (2012–2014; n = 577), a longitudinal cohort of women with past GDM from the Danish National Birth Cohort (1996–2002), we assessed associations of cumulative lactation duration (none, 2 (IQR 24.6, 33.0); 28.6% of participants had T2D, 39.7% had prediabetes, and 41.2% had obesity. Relative risks (95% CI) of T2D for 0–6, 6–12, 12–24, and ≥24 months of cumulative lactation duration compared to none were 0.94 (0.62,1.44), 0.88 (0.59,1.32), 0.73 (0.46,1.17), and 0.71 (0.40,1.27), respectively. Cumulative lactation duration was not significantly associated with any other clinical outcome or continuous biomarker. In this high-risk cohort of middle-aged women with past GDM, T2D, prediabetes, and obesity were common at follow-up, but not associated with history of cumulative lactation duration 9–16 years after the index pregnancy. Further studies in diverse populations among women at mid-age are needed to understand associations of breastfeeding with T2D.
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- 2022
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11. Understanding the Relation Between Self-Compassion and Suicide Risk Among Adolescents in a Post-disaster Context: Mediating Roles of Gratitude and Posttraumatic Stress Disorder
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Aiyi Liu, Wenchao Wang, and Xinchun Wu
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self-compassion ,gratitude ,PTSD ,suicide risk ,adolescents ,Psychology ,BF1-990 - Abstract
BackgroundThe suicide risk among adolescents post-earthquake remains an important issue in trauma psychology. While existing studies and theories suggest that factors such as self-compassion, gratitude, and posttraumatic stress disorder (PTSD) play roles in the risk of suicide, few studies have combined these factors to explore the relationship between them.ObjectiveThis study examined the mediating roles of gratitude and PTSD in the relationship between self-compassion and suicide risk among Chinese adolescents after the Ya’an earthquake.MethodsFour and a half years after the Ya’an earthquake, 499 middle school students in Lushan County were assessed using the following systems: Measures of Self-Compassion Scale, Gratitude Questionnaire, PTSD Checklist for DSM-5, and Child Behavior Problems Questionnaire.ResultsWhen we controlled for gender, age, and traumatic exposure, in the direct effect model, positive self-compassion had a negative effect on suicide risk, and negative self-compassion had a positive effect on suicide risk. In the indirect effects model, both positive self-compassion and negative self-compassion had no significant direct effect on suicide risk. Moreover, we found an indirect and negative effect of positive self-compassion on suicide risk via gratitude and PTSD, as well as via an indirect path from gratitude to PTSD. On the other hand, we also found an indirect and positive effect of negative self-compassion on suicide risk via gratitude and PTSD, as well as via an indirect path from gratitude to PTSD.ConclusionPositive self-compassion reduces the risk of suicide, while negative self-compassion increases the risk of suicide. Gratitude and PTSD play significant mediating role between self-compassion and suicide risk.
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- 2020
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12. GATE: an efficient procedure in study of pleiotropic genetic associations
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Wei Zhang, Liu Yang, Larry L. Tang, Aiyi Liu, James L. Mills, Yuanchang Sun, and Qizhai Li
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Pleiotropic genetic associations ,Principal component analysis ,Power ,Biomedical study ,Biotechnology ,TP248.13-248.65 ,Genetics ,QH426-470 - Abstract
Abstract Background The association studies on human complex traits are admittedly propitious to identify deleterious genetic markers. Compared to single-trait analyses, multiple-trait analyses can arguably make better use of the information on both traits and markers, and thus improve statistical power of association tests prominently. Principal component analysis (PCA) is a well-known useful tool in multivariate analysis and can be applied to this task. Generally, PCA is first performed on all traits and then a certain number of top principal components (PCs) that explain most of the trait variations are selected to construct the test statistics. However, under some situations, only utilizing these top PCs would lead to a loss of important evidences from discarded PCs and thus makes the capability compromised. Methods To overcome this drawback while keeping the advantages of using the top PCs, we propose a group accumulated test evidence (GATE) procedure. By dividing the PCs which is sorted in the descending order according to the corresponding eigenvalues into a few groups, GATE integrates the information of traits at the group level. Results Simulation studies demonstrate the superiority of the proposed approach over several existing methods in terms of statistical power. Sometimes, the increase of power can reach 25%. These methods are further illustrated using the Heterogeneous Stock Mice data which is collected from a quantitative genome-wide association study. Conclusions Overall, GATE provides a powerful test for pleiotropic genetic associations.
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- 2017
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13. Misrouting of v-ATPase subunit V0a1 dysregulates lysosomal acidification in a neurodegenerative lysosomal storage disease model
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Maria B. Bagh, Shiyong Peng, Goutam Chandra, Zhongjian Zhang, Satya P. Singh, Nagarajan Pattabiraman, Aiyi Liu, and Anil B. Mukherjee
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Science - Abstract
Lysosomal acidification defects have been implicated in various neurodegenerative disorders. Baghet al. show that the V0a1 subunit of v-ATPase requires palmitoylation for correct sorting and trafficking to the lysosome membrane, and that such a process is impaired in a mouse model of a devastating neurodegenerative lysosomal storage disease, INCL.
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- 2017
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14. On the Use of Min-Max Combination of Biomarkers to Maximize the Partial Area under the ROC Curve
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Hua Ma, Susan Halabi, and Aiyi Liu
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Probabilities. Mathematical statistics ,QA273-280 - Abstract
Background. Evaluation of diagnostic assays and predictive performance of biomarkers based on the receiver operating characteristic (ROC) curve and the area under the ROC curve (AUC) are vital in diagnostic and targeted medicine. The partial area under the curve (pAUC) is an alternative metric focusing on a range of practical and clinical relevance of the diagnostic assay. In this article, we adopt and extend the min-max method to the estimation of the pAUC when multiple continuous scaled biomarkers are available and compare the performances of our proposed approach with existing approaches via simulations. Methods. We conducted extensive simulation studies to investigate the performance of different methods for the combination of biomarkers based on their abilities to produce the largest pAUC estimates. Data were generated from different multivariate distributions with equal and unequal variance-covariance matrices. Different shapes of the ROC curves, false positive fraction ranges, and sample size configurations were considered. We obtained the mean and standard deviation of the pAUC estimates through re-substitution and leave-one-pair-out cross-validation. Results. Our results demonstrate that the proposed method provides the largest pAUC estimates under the following three important practical scenarios: (1) multivariate normally distributed data for nondiseased and diseased participants have unequal variance-covariance matrices; or (2) the ROC curves generated from individual biomarker are relative close regardless of the latent normality distributional assumption; or (3) the ROC curves generated from individual biomarker have straight-line shapes. Conclusions. The proposed method is robust and investigators are encouraged to use this approach in the estimation of the pAUC for many practical scenarios.
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- 2019
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15. The Joint Role of Thyroid Function and Iodine Status on Risk of Preterm Birth and Small for Gestational Age: A Population-Based Nested Case-Control Study of Finnish Women
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Alexandra C. Purdue-Smithe, Tuija Männistö, Griffith A. Bell, Sunni L. Mumford, Aiyi Liu, Kurunthachalam Kannan, Un-Jung Kim, Eila Suvanto, Heljä-Marja Surcel, Mika Gissler, and James L. Mills
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iodine ,thyroid hormones ,thyroglobulin ,thyroid stimulating hormone ,pregnancy ,preterm birth ,small for gestational age ,Nutrition. Foods and food supply ,TX341-641 - Abstract
Normal maternal thyroid function during pregnancy is essential for fetal development and depends upon an adequate supply of iodine. Little is known about how iodine status is associated with preterm birth and small for gestational age (SGA) in mildly iodine insufficient populations. Our objective was to evaluate associations of early pregnancy serum iodine, thyroglobulin (Tg), and thyroid-stimulating hormone (TSH) with odds of preterm birth and SGA in a prospective, population-based, nested case-control study from all births in Finland (2012−2013). Cases of preterm birth (n = 208) and SGA (n = 209) were randomly chosen from among all singleton births. Controls were randomly chosen from among singleton births that were not preterm (n = 242) or SGA (n = 241) infants during the same time period. Women provided blood samples at 10−14 weeks’ gestation for serum iodide, Tg and TSH measurement. We used logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for preterm birth and SGA. Each log-unit increase in serum iodide was associated with higher odds of preterm birth (adjusted OR = 1.19, 95% CI = 1.02−1.40), but was not associated with SGA (adjusted OR = 1.01, 95% CI = 0.86−1.18). Tg was not associated with preterm birth (OR per 1 log-unit increase = 0.87, 95% CI = 0.73−1.05), but was inversely associated with SGA (OR per log-unit increase = 0.78, 95% CI = 0.65−0.94). Neither high nor low TSH (versus normal) were associated with either outcome. These findings suggest that among Finnish women, iodine status is not related to SGA, but higher serum iodide may be positively associated with preterm birth.
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- 2019
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16. Lactation Duration and Long-Term Thyroid Function: A Study among Women with Gestational Diabetes
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Pranati L. Panuganti, Stefanie N. Hinkle, Shristi Rawal, Louise G. Grunnet, Yuan Lin, Aiyi Liu, Anne C. B. Thuesen, Sylvia H. Ley, Sjurdur F. Olesen, and Cuilin Zhang
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GDM ,lactation ,thyroid ,triiodothyronine ,thyroxine ,thyroid antibodies ,Nutrition. Foods and food supply ,TX341-641 - Abstract
Lactation is associated with reduced postpartum weight retention and a lower risk of several cardiometabolic disorders in population-based studies. We examined the association between lactation and long-term thyroid function among women with history of gestational diabetes mellitus (GDM), a high-risk population for subsequent metabolic complications. The study included 550 women who developed GDM in the Danish National Birth Cohort (1996–2002) and followed-up in the Diabetes & Women’s Health Study (2012–2014). We assessed adjusted associations between cumulative lactation duration and concentrations of thyroid stimulating hormone (TSH), free triiodothyronine (fT3), and free thyroxine (fT4) measured at follow-up. Women with longer cumulative lactation duration tended to have higher fT3 levels (adjusted β and 95% confidence interval (CI) for ≥12 months vs. none: 0.19 (0.03–0.36); p-trend = 0.05). When restricted to women with a single lifetime pregnancy to control for parity (n = 70), women who lactated for >6 months (vs. none) had higher fT3 levels (0.46 pmol/L (0.12–0.80); p-trend = 0.02) and a higher fT3:fT4 ratio (0.61 (0.17–1.05); p-trend = 0.007). Our findings suggested that a longer duration of lactation may be related to greater serum fT3 levels and fT3:fT4 ratio 9–16 years postpartum among Danish women with a history of GDM. The association was particularly pronounced among women who only had one lifetime pregnancy.
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- 2018
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17. The Cell Surface Estrogen Receptor, G Protein- Coupled Receptor 30 (GPR30), is Markedly Down Regulated During Breast Tumorigenesis
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Indira Poola, Jessy Abraham, Aiyi Liu, Josephine J. Marshalleck, and Robert L. DeWitty
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breast tumorigenesis ,estrogen signaling ,G protein coupled receptor 30 (GPR30) ,cell surface estrogen receptor and lymph node metastasis ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Background: GPR30 is a cell surface estrogen receptor that has been shown to mediate a number of non-genomic rapid effects of estrogen and appear to balance the signaling of estrogen and growth factors. In addition, progestins appear to use GPR30 for their actions. Therefore, GPR30 could play a critical role in hormonal regulation of breast epithelial cell integrity. Deregulation of the events mediated by GPR30 could contribute to tumorigenesis.Methods: To understand the role of GPR30 in the deregulation of estrogen signaling processes during breast carcinogenesis, we have undertaken this study to investigate its expression at mRNA levels in tumor tissues and their matched normal tissues. We compared its expression at mRNA levels by RT quantitative real-time PCR relative to GAPDH in ERα”—positive (n = 54) and ERα”—negative (n = 45) breast cancer tissues to their matched normal tissues.Results: We report here, for the first time, that GPR30 mRNA levels were significantly down-regulated in cancer tissues in comparison with their matched normal tissues (p 0.0001 by two sided paired t-test). The GPR30 expression levels were significantly lower in tumor tissues from patients (n = 29) who had lymph node metastasis in comparison with tumors from patients (n = 53) who were negative for lymph node metastasis (two sample t-test, p 0.02), but no association was found with ERα, PR and other tumor characteristics.Conclusions: Down-regulation of GPR30 could contribute to breast tumorigenesis and lymph node metastasis.
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- 2008
18. OUCopula: Bi-Channel Multi-Label Copula-Enhanced Adapter-Based CNN for Myopia Screening Based on OU-UWF Images.
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Yang Li, Qiuyi Huang, Chong Zhong, Danjuan Yang, Meiyan Li, A. H. Welsh, Aiyi Liu, Bo Fu, Catherine C. Liu, and Xingtao Zhou
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- 2024
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19. Distance-Based Regression Analysis for Measuring Associations.
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Yuke Shi, Wei Zhang, Aiyi Liu, and Qizhai Li
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- 2023
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20. An adaptive direction-assisted test for microbiome compositional data.
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Wei Zhang, Aiyi Liu, Zhiwei Zhang, Guanjie Chen, and Qizhai Li
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- 2022
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21. The reciprocal relations among self-compassion, posttraumatic stress disorder, and posttraumatic growth among adolescents after the Jiuzhaigou earthquake: a three-wave cross-lagged study
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Aiyi Liu, Boya Xu, Mingxiao Liu, Wenchao Wang, and Xinchun Wu
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Psychiatry and Mental health ,General Medicine - Published
- 2023
22. SummaryAUC: a tool for evaluating the performance of polygenic risk prediction models in validation datasets with only summary level statistics.
- Author
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Lei Song, Aiyi Liu, Jianxin Shi, and Molecular Genetics of Schizophrenia Consortium
- Published
- 2019
- Full Text
- View/download PDF
23. Supplementary Tables 1-3 from Mitochondrial Genetic Background Modifies Breast Cancer Risk
- Author
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Lee-Jun C. Wong, Aiyi Liu, Daniel Covarrubias, Suzanne M. Leal, and Ren-Kui Bai
- Abstract
Supplementary Tables 1-3 from Mitochondrial Genetic Background Modifies Breast Cancer Risk
- Published
- 2023
24. Data from Mitochondrial Genetic Background Modifies Breast Cancer Risk
- Author
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Lee-Jun C. Wong, Aiyi Liu, Daniel Covarrubias, Suzanne M. Leal, and Ren-Kui Bai
- Abstract
Inefficient mitochondrial electron transport chain (ETC) function has been implicated in the vicious cycle of reactive oxygen species (ROS) production that may predispose an individual to late onset diseases, such as diabetes, hypertension, and cancer. Mitochondrial DNA (mtDNA) variations may affect the efficiency of ETC and ROS production, thus contributing to cancer risk. To test this hypothesis, we genotyped 69 mtDNA variations in 156 unrelated European-American females with familial breast cancer and 260 age-matched European-American female controls. Fisher's exact test was done for each single-nucleotide polymorphism (SNP)/haplogroup and the P values were adjusted for multiple testing using permutation. Odds ratio (OR) and its 95% confidence interval (95% CI) were calculated using the Sheehe correction. Among the 69 variations, 29 were detected in the study subjects. Three SNPs, G9055A (OR, 3.03; 95% CI, 1.63–5.63; P = 0.0004, adjusted P = 0.0057), A10398G (OR, 1.79; 95% CI, 1.14–2.81; P = 0.01, adjusted P = 0.19), and T16519C (OR, 1.98; 95% CI, 1.25–3.12; P = 0.0030, adjusted P = 0.0366), were found to increase breast cancer risk; whereas T3197C (OR, 0.31; 95% CI, 0.13–0.75; P = 0.0043, adjusted P = 0.0526) and G13708A (OR, 0.47; 95% CI, 0.24–0.92; P = 0.022, adjusted P = 0.267) were found to decrease breast cancer risk. Overall, individuals classified as haplogroup K show a significant increase in the risk of developing breast cancer (OR, 3.03; 95% CI, 1.63–5.63; P = 0.0004, adjusted P = 0.0057), whereas individuals bearing haplogroup U have a significant decrease in breast cancer risk (OR, 0.37; 95% CI, 0.19–0.73; P = 0.0023, adjusted P = 0.03). Our results suggest that mitochondrial genetic background plays a role in modifying an individual's risk to breast cancer. [Cancer Res 2007;67(10):4687–94]
- Published
- 2023
25. Empathy and Self-Compassion Mediate the Relationships between Parental Attachment, Prosocial Behavior, and Antisocial Behavior among Adolescents after the Jiuzhaigou Earthquake
- Author
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Aiyi Liu, Wenchao Wang, Xinchun Wu, and Boya Xu
- Abstract
Objective This study examined the mediating roles of empathy and self-compassion in the relationship between parental attachment, prosocial behavior, and antisocial behavior among Chinese adolescents after the Jiuzhaigou earthquake. Methods A total of 411 adolescents (M = 14.73, SD = 0.91) were assessed 16 months after the Jiuzhaigou earthquake using self-report questionnaires of trauma exposure, parental attachment, empathy, self-compassion, prosocial behavior, and antisocial behavior. Results The parental attachment had a positive effect on prosocial behavior via empathy and positive self-compassion, as well as via an indirect path from empathy to positive self-compassion. Parental attachment had a negative effect on antisocial behavior via empathy and negative self-compassion, and had an indirect path from empathy to negative self-compassion. Conclusions These findings indicate that enhancing parental attachment may promote prosocial behavior and reduce antisocial behavior of post-earthquake adolescents. Empathy and self-compassion play significant mediating roles between parental attachment, prosocial behavior, and antisocial behavior.
- Published
- 2023
26. The reciprocal relations among self‐compassion, and depression among adolescents after the Jiuzhaigou earthquake: A three‐wave cross‐lagged study
- Author
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Aiyi Liu, Boya Xu, Mingxiao Liu, Wenchao Wang, and Xinchun Wu
- Subjects
Clinical Psychology ,Arts and Humanities (miscellaneous) - Published
- 2023
27. Relationship between self-compassion and nonsuicidal self-injury in middle school students after earthquake: Gender differences in the mediating effects of gratitude and posttraumatic growth
- Author
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Aiyi Liu, Wenchao Wang, Xinchun Wu, and Boya Xu
- Subjects
Clinical Psychology ,Social Psychology - Published
- 2023
28. Multiple Decrements in Switch Task Performance in Female Rats Exposed to Space Radiation
- Author
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Samuel D. Stephenson, Aiyi Liu, Ashley Blackwell, and Richard A. Britten
- Published
- 2023
29. Marginal, conditional, and pseudo likelihood ratio approaches for biomarker combination to predict a binary disease outcome
- Author
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Danping Liu, Yongli Han, and Aiyi Liu
- Subjects
Statistics and Probability ,Likelihood Functions ,ROC Curve ,Autism Spectrum Disorder ,Epidemiology ,Humans ,Computer Simulation ,Child ,Biomarkers - Abstract
It is a common practice in public health research that multiple biomarkers are collected to diagnose or predict a disease outcome. A natural question is how to combine multiple biomarkers to improve the diagnostic accuracy. It has been shown by Neyman-Pearson lemma that the likelihood ratio statistic achieves the optimal AUC in theory. However, practical difficulty often lies in the estimation of the multivariate density functions. We propose three novel methods for the biomarker combination, with the idea of breaking down the joint densities to a series of univariate densities. The marginal likelihood ratio approach only assumes the marginal distribution of each biomarker. While the conditional likelihood ratio (CLR) and pseudo likelihood ratio (PLR) approaches assume the conditional distributions of a marker given others, and hence make use of the correlation structure to estimate the combination rules. The proposed methods make it much easier to assume and validate the univariate distributions of a biomarker than making multivariate distributional assumptions. Extensive simulation studies demonstrate that the CLR and the PLR approaches outperform many existing methods, and are therefore recommended for practical use. The proposed methods are motivated by and applied to a biomarker study to diagnose childhood autism/autism spectrum disorder.
- Published
- 2022
30. Multiple decrements in switch task performance in female rats exposed to space radiation
- Author
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Samuel Stephenson, Aiyi Liu, Ashley A. Blackwell, and Richard A. Britten
- Subjects
Behavioral Neuroscience - Published
- 2023
31. Data-adaptive efficient estimation strategies for biomarker studies embedded in randomized trials
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Wei Zhang, Zhiwei Zhang, James F. Troendle, and Aiyi Liu
- Subjects
Statistics and Probability ,Modeling and Simulation ,Statistics, Probability and Uncertainty - Published
- 2022
32. Estimation of partial derivative functionals with application to human mortality data analysis
- Author
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Aiyi Liu, Zhaohai Li, Tao Zhang, and Qingzhao Zhang
- Subjects
Estimation ,Functional principal component analysis ,Random surface ,Mortality data ,General Mathematics ,Time dynamics ,Functional data analysis ,Applied mathematics ,Partial derivative ,Representation (mathematics) ,Mathematics - Abstract
To better describe and understand the time dynamics in functional data analysis, it is often desirable to recover the partial derivatives of the random surface. A novel approach is proposed based on marginal functional principal component analysis to derive the representation for partial derivatives. To obtain the Karhunen-Loeve expansion of the partial derivatives, an adaptive estimation is explored. Asymptotic results of the proposed estimates are established. Simulation studies show that the proposed methods perform well in finite samples. Application to the human mortality data reveals informative time dynamics in mortality rates.
- Published
- 2021
33. The mediating role of rumination in the relation between self-compassion, posttraumatic stress disorder, and posttraumatic growth among adolescents after the Jiuzhaigou earthquake
- Author
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Xinchun Wu, Wenchao Wang, and Aiyi Liu
- Subjects
Posttraumatic growth ,05 social sciences ,050109 social psychology ,Ptsd checklist ,Cognition ,behavioral disciplines and activities ,050105 experimental psychology ,Posttraumatic stress ,mental disorders ,Rumination ,medicine ,0501 psychology and cognitive sciences ,medicine.symptom ,Psychology ,General Psychology ,Self-compassion ,Clinical psychology - Abstract
Previous studies indicated that self-compassion can alleviate posttraumatic stress disorder (PTSD) and promote posttraumatic growth (PTG). Rumination is a cognitive process in which individuals repeatedly think about traumatic events and their consequences, which includes invasive rumination (IR) and deliberate rumination (DR). IR is a process of thoughts over traumatic event that invades the cognitive world in an undesired state, whereas DR is an individual’s conscious and repeated thinking on events. IR and DR have also been shown to have effects on PTSD and PTG. Studies have examined the relationship between self-compassion, IR, deliberate rumination DR, PTSD, and PTG, respectively, but only a few studies have examined their combined roles in PTSD and PTG among adolescents who have experienced an earthquake. In addition, recent studies have shown that the positive and negative components of self-compassion have different effects on post-traumatic stress responses, but few studies have explored the mechanisms of positive and negative self-compassion on PTSD and PTG in adolescents who experience earthquakes. This study examines the mediating roles of rumination in the relationship between self-compassion, PTSD and PTG among Chinese adolescents after the Jiuzhaigou earthquake. Ten months after the Jiuzhaigou earthquake, a questionnaire survey was conducted among 621 middle school students in Jiuzhaigou county. The participants were assessed by using the following systems: Trauma Exposure Questionnaire, Self-Compassion Scale, Event-Related Rumination Inventory, PTSD Checklist for DSM-5, and Posttraumatic Growth Inventory. When we controlled for the gender, age, and trauma exposure in the direct effect model, positive self-compassion (PSC) had a negative effect on PTSD and a positive effect on PTG. Moreover, negative self-compassion (NSC) had a positive effect on PTSD, but the effect on PTG was nonsignificant. In the indirect model, PSC had an indirect and positive effect on PTSD and PTG via deliberate rumination (DR). NSC had an indirect and positive effect on PTSD and PTG via invasive rumination (IR), whereas NSC also had an indirect and negative effect on PTSD and PTG, as well as via an indirect path from IR to DR on PTSD and PTG. Findings indicated that increased PSC may reduce PTSD and be beneficial for PTG. NSC may exacerbate PTSD. Rumination plays a significant mediating role between self-compassion, PTSD, and PTG.
- Published
- 2021
34. In a mouse model of <scp>INCL</scp> reduced S‐palmitoylation of cytosolic thioesterase <scp>APT1</scp> contributes to microglia proliferation and neuroinflammation
- Author
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Avisek Mondal, Abhilash P. Appu, Aiyi Liu, Wei Zhang, Tamal Sadhukhan, Maria B. Bagh, and Anil B. Mukherjee
- Subjects
Male ,Lipoylation ,Mice ,03 medical and health sciences ,Palmitoylation ,Neuronal Ceroid-Lipofuscinoses ,Lysosome ,Genetics ,medicine ,Animals ,Humans ,Cells, Cultured ,Genetics (clinical) ,Neuroinflammation ,Cell Proliferation ,030304 developmental biology ,Mice, Knockout ,0303 health sciences ,Microglia ,Chemistry ,030305 genetics & heredity ,PPT1 ,Cell biology ,Mice, Inbred C57BL ,Disease Models, Animal ,Cytosol ,HEK293 Cells ,medicine.anatomical_structure ,Astrocytes ,Mutation ,Saturated fatty acid ,Female ,lipids (amino acids, peptides, and proteins) ,Thiolester Hydrolases ,Signal transduction - Abstract
S-palmitoylation is a reversible posttranslational modification in which a 16-carbon saturated fatty acid (generally palmitate) is attached to specific cysteine residues in polypeptides via thioester linkage. Dynamic S-palmitoylation (palmitoylation-depalmitoylation), like phosphorylation-dephosphorylation, regulates the function of numerous proteins, especially in the brain. While a family of 23 palmitoyl-acyl transferases (PATS), commonly known as ZDHHCs, catalyze S-palmitoylation of proteins, the thioesterases, localized either in the cytoplasm (eg, APT1) or in the lysosome (eg, PPT1) mediate depalmitoylation. Previously, we reported that APT1 requires dynamic S-palmitoylation for shuttling between the cytosol and the plasma membrane. APT1 depalmitoylated H-Ras to regulate its signaling pathway that stimulates cell proliferation. Although we demonstrated that APT1 catalyzed its own depalmitoylation, the ZDHHC(s) that S-palmitoylated APT1 had remained unidentified. We report here that ZDHHC5 and ZDHHC23 catalyze APT1 S-palmitoylation. Intriguingly, lysosomal Ppt1-deficiency in Cln1-/- mouse, a reliable animal model of INCL, markedly reduced ZDHHC5 and ZDHHC23 levels. Remarkably, in the brain of these mice decreased ZDHHC5 and ZDHHC23 levels suppressed membrane-bound APT1, thereby, increasing plasma membrane-localized H-Ras, which activated its signaling pathway stimulating microglia proliferation. Increased inflammatory cytokines produced by microglia together with increased complement C1q level contributed to the transformation of astrocytes to neurotoxic A1 phenotype. Importantly, neuroinflammation was ameliorated by treatment of Cln1-/- mice with a PPT1-mimetic small molecule, N-tert(Butyl)hydroxylamine (NtBuHA). Our results revealed a novel pathway to neuropathology in an INCL mouse model and uncovered a previously unrecognized mechanism of the neuroprotective actions of NtBuHA and its potential as a drug target.
- Published
- 2021
35. On the design and the analysis of stratified biomarker trials in the presence of measurement error
- Author
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Susan Halabi, Chen-Yen Lin, and Aiyi Liu
- Subjects
Statistics and Probability ,Oncology ,medicine.medical_specialty ,Epidemiology ,01 natural sciences ,Article ,law.invention ,010104 statistics & probability ,03 medical and health sciences ,Event outcome ,Clinical Trials, Phase II as Topic ,0302 clinical medicine ,Bias ,Randomized controlled trial ,law ,Internal medicine ,medicine ,Humans ,030212 general & internal medicine ,0101 mathematics ,Randomized Controlled Trials as Topic ,Retrospective Studies ,Random assignment ,business.industry ,Precision medicine ,Confidence interval ,Clinical trial ,Clinical Trials, Phase III as Topic ,Research Design ,Sample size determination ,Sample Size ,Biomarker (medicine) ,business ,Biomarkers - Abstract
A major emphasis in precision medicine is to optimally treat subgroups of patients who may benefit from certain therapeutic agents. And as such, enormous resources and innovative clinical trials designs in oncology are devoted to identifying predictive biomarkers. Predictive biomarkers are ones that will identify patients that are more likely to respond to specific therapies and they are usually discovered through retrospective analysis from large randomized phase II or phase III trials. One important design to consider is the stratified biomarker design, where patients will have their specimens obtained at baseline and the biomarker status will be assessed prior to random assignment. Regardless of their biomarker status, patients will be randomized to either an experimental arm or the standard of care arm. The stratified biomarker design can be used to test for a treatment-biomarker interaction in predicting a time-to event outcome. Many biomarkers, however, are derived from tissues from patients, and their levels may be heterogeneous. As a result, biomarker levels may be measured with error and this would have an adverse impact on the power of a stratified biomarker clinical trial. We present a trial design and an analysis framework for the stratified biomarker design. We show that the naïve test is biased and provide bias-corrected estimators for computing the sample size and the 95% confidence interval when testing for a treatment-biomarker interaction in predicting a time to event outcome. We propose a sample size formula that adjusts for misclassification and apply it in the design of a phase III clinical trial in renal cancer.
- Published
- 2021
36. Abstract 1502: Misrouting of Niemann-Pick C1 protein mediates cholesterol induced mTORC1-activation contributing to pathogenesis of CLN1-disease
- Author
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Abhilash Puthuvelvippel Appu, Maria Bagh, Nisha Plavelil, Avisek Mondal, Tamal Sadhukhan, Aiyi Liu, and Anil Mukherjee
- Subjects
Cell Biology ,Molecular Biology ,Biochemistry - Published
- 2023
37. Error‐corrected estimation of a diagnostic accuracy index of a biomarker against a continuous gold standard
- Author
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Mixia Wu, Aiyi Liu, Xiaoyu Zhang, Xu Zhang, and Wei Zhang
- Subjects
Statistics and Probability ,Index (economics) ,Observational error ,Epidemiology ,Reproducibility of Results ,Asymptotic distribution ,Estimator ,Diagnostic accuracy ,Gold standard (test) ,Consistency (statistics) ,Data Interpretation, Statistical ,Statistics ,Humans ,Biomarker (medicine) ,Computer Simulation ,Child ,Biomarkers ,Mathematics - Abstract
This article concerns evaluating the effectiveness of a continuous diagnostic biomarker against a continuous gold standard that is measured with error. Extending the work of Obuchowski (2005, 2016), Wu et al (2016) suggested an accuracy index and proposed an estimator for the index with error-prone standard when the reliability coefficient is known. Combining with additional measurements (without measurement errors) on the continuous gold standard collected from some subjects, this article proposes two adaptive estimators of the accuracy index when the reliability coefficient is unknown, and further establish the consistency and asymptotic normality of these estimators. Simulation studies are conducted to compare various estimators. Data from an intervention trial on glycemic control among children with type 1 diabetes are used to illustrate the proposed methods.
- Published
- 2020
38. Ppt1-deficiency dysregulates lysosomal Ca(++)-homeostasis contributing to pathogenesis in a mouse model of CLN1 disease
- Author
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Avisek Mondal, Abhilash P. Appu, Tamal Sadhukhan, Maria B. Bagh, Rafael M. Previde, Sriparna Sadhukhan, Stanko Stojilkovic, Aiyi Liu, and Anil B. Mukherjee
- Subjects
Mice, Knockout ,Membrane Proteins ,Article ,Lipofuscin ,Disease Models, Animal ,Mice ,Neuronal Ceroid-Lipofuscinoses ,Genetics ,Animals ,Homeostasis ,Humans ,Calcium ,Thiolester Hydrolases ,Lysosomes ,Genetics (clinical) ,Acyltransferases - Abstract
Inactivating mutations in the PPT1 gene encoding palmitoyl-protein thioesterase-1 (PPT1) underlie the CLN1 disease, a devastating neurodegenerative lysosomal storage disorder. The mechanism of pathogenesis underlying CLN1 disease has remained elusive. PPT1 is a lysosomal enzyme, which catalyzes the removal of palmitate from S-palmitoylated proteins (constituents of ceroid lipofuscin) facilitating their degradation and clearance by lysosomal hydrolases. Thus, it has been proposed that Ppt1-deficiency leads to lysosomal accumulation of ceroid lipofuscin leading to CLN1 disease. While S-palmitoylation is catalyzed by palmitoyl acyltransferases (called ZDHHCs), palmitoyl-protein thioesterases (PPTs) depalmitoylate these proteins. We sought to determine the mechanism by which Ppt1-deficiency may impair lysosomal degradative function leading to INCL pathogenesis. Here we report that in Ppt1(−/−) mice, which mimic CLN1 disease, low level of inositol 3-phosphate receptor-1 (IP3R1) that mediates Ca(++)-transport from the ER to the lysosome dysregulated lysosomal Ca(++) homeostasis. Intriguingly, the transcription factor NFATC4, which regulates IP3R1-expression, required S-palmitoylation for trafficking from the cytoplasm to the nucleus. We identified two palmitoyl acyltransferases, ZDHHC4 and ZDHHC8, which catalyzed S-palmitoylation of NFATC4. Notably, in Ppt1(−/−) mice, reduced ZDHHC4 and ZDHHC8 levels markedly lowered S-palmitoylated NFATC4 (active) in the nucleus, which inhibited IP3R1-expression, thereby, dysregulating lysosomal Ca(++) homeostasis. Consequently, Ca(++)-dependent lysosomal enzyme activities were markedly suppressed. Impaired lysosomal degradative function impaired autophagy, which caused lysosomal storage of undigested cargo. Importantly, IP3R1-overexpression in Ppt1(−/−) mouse fibroblasts ameliorated this defect. Our results reveal a previously unrecognized role of Ppt1 in regulating lysosomal Ca(++)-homeostasis and suggest that this defect contributes to pathogenesis of CLN1 disease.
- Published
- 2022
39. Exact inference on contrasts in means of intraclass correlation models with missing responses.
- Author
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Mi-Xia Wu, Kai F. Yu, and Aiyi Liu
- Published
- 2009
- Full Text
- View/download PDF
40. Reward-related eating, self-regulation, and weight change in pregnancy and postpartum: the Pregnancy Eating Attributes Study (PEAS)
- Author
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Kyle S. Burger, Alison M. Stuebe, Leah M. Lipsky, Myles S. Faith, Aiyi Liu, Wanda K. Nicholson, Anna Maria Siega-Riz, and Tonja R. Nansel
- Subjects
Adult ,Endocrinology, Diabetes and Metabolism ,Medicine (miscellaneous) ,030209 endocrinology & metabolism ,Impulsivity ,Article ,Self-Control ,03 medical and health sciences ,0302 clinical medicine ,Reward ,Pregnancy ,Humans ,Medicine ,Prospective Studies ,030212 general & internal medicine ,Yale Food Addiction Scale ,Nutrition and Dietetics ,business.industry ,Postpartum Period ,digestive, oral, and skin physiology ,Weight change ,medicine.disease ,Gestational Weight Gain ,Food ,Cohort ,Gestation ,Female ,Observational study ,medicine.symptom ,business ,Weight gain ,Demography - Abstract
Background/Objectives. Reward-related eating is hypothesized to underlie risk for weight gain in obesogenic environments, but its role is unknown during pregnancy and postpartum when weight change is normative, but excess weight gain and weight retention are common. This study examined associations of self-reported reward-related eating, self-regulation, and the home food environment with excessive gestational weight gain (GWG) and postpartum weight change. Subjects/Methods. Participants in the Pregnancy Eating Attributes Study observational cohort were enrolled at ≤12 weeks pregnancy and followed through one-year postpartum (458 recruited; 367 retained through delivery). Participants completed four measures of reward-related eating – Modified Yale Food Addiction Scale, Power of Food Scale, Multiple Choice Procedure, and a Reinforcing Value of Food Questionnaire; two measures of self-regulation – Barratt Impulsiveness Scale and Delay of Gratification Inventory; and a Home Food Inventory. Measured weight and skinfolds were obtained. Multinomial logistic and multiple linear regression analyses estimated associations of reward-related eating, self-regulation, and home food environment with excessive GWG, gestational fat gain, postpartum weight change, and percent of GWG retained. Results. Excessive GWG was associated with food reinforcement intensity, but not with any other measure of reward-related eating, self-regulation, or home food environment. Greater gestational fat gain was associated only with higher Multiple Choice Procedure. Postpartum weight change and percent of GWG retained were associated with greater Delay of Gratification and obesogenic home food environment, but not with any measure of reward-related eating or with impulsivity. Conclusions. Findings do not support the hypothesis that self-reported reward-related eating is associated with weight outcomes in pregnancy and postpartum but indicate a relation of Delay of Gratification with postpartum weight retention. Further research using both surveys and objective measures of reward-related eating is needed to advance our understanding of the relation of reward-related eating with weight changes during this critical period of a woman’s life.
- Published
- 2020
41. Score and deviance residuals based on the full likelihood approach in survival analysis
- Author
-
Yuan Wu, Aiyi Liu, Susan Halabi, and Sandipan Dutta
- Subjects
Male ,Pharmacology ,Statistics and Probability ,Likelihood Functions ,Models, Statistical ,Time Factors ,Liver Cirrhosis, Biliary ,Proportional hazards model ,Breast Neoplasms ,Deviance (statistics) ,Residual ,Survival Analysis ,Article ,Research Design ,Data Interpretation, Statistical ,Statistics ,Outlier ,Humans ,Computer Simulation ,Female ,Pharmacology (medical) ,Statistical graphics ,Survival analysis ,Proportional Hazards Models ,Mathematics - Abstract
Assuming the proportional hazards model and non-informative censoring, the full likelihood approach is used to obtain two new residuals. The first residual is based on the ideas used in obtaining score-type residuals similar to the partial likelihood approach. The second type of residual is based on the concept of deviance residuals. Extensive simulations are conducted to compare the performance of the residuals from the full likelihood based approach with those of the partial likelihood method. We demonstrate through simulation studies that the full likelihood based residuals are more efficient than their partial likelihood counterpart in identifying potential outliers when the censoring proportion is high. The graphical techniques are used to illustrate the applications of these residuals using some examples.
- Published
- 2020
42. Nonparametric estimation of distributions and diagnostic accuracy based on group‐tested results with differential misclassification
- Author
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Qizhai Li, Paul S. Albert, Wei Zhang, and Aiyi Liu
- Subjects
Statistics and Probability ,National Health and Nutrition Examination Survey ,Computer science ,Population ,Coverage probability ,01 natural sciences ,Article ,General Biochemistry, Genetics and Molecular Biology ,010104 statistics & probability ,03 medical and health sciences ,Bias ,Statistics ,Humans ,0101 mathematics ,education ,030304 developmental biology ,Estimation ,0303 health sciences ,education.field_of_study ,Models, Statistical ,General Immunology and Microbiology ,Receiver operating characteristic ,Applied Mathematics ,Nonparametric statistics ,Estimator ,General Medicine ,Nutrition Surveys ,Group testing ,Research Design ,General Agricultural and Biological Sciences ,Statistical Distributions - Abstract
This article concerns the problem of estimating a continuous distribution in a diseased or nondiseased population when only group-based test results on the disease status are available. The problem is challenging in that individual disease statuses are not observed and testing results are often subject to misclassification, with further complication that the misclassification may be differential as the group size and the number of the diseased individuals in the group vary. We propose a method to construct nonparametric estimation of the distribution and obtain its asymptotic properties. The performance of the distribution estimator is evaluated under various design considerations concerning group sizes and classification errors. The method is exemplified with data from the National Health and Nutrition Examination Survey study to estimate the distribution and diagnostic accuracy of C-reactive protein in blood samples in predicting chlamydia incidence.
- Published
- 2020
43. Order‐restricted inference for clustered ROC data with application to fingerprint matching accuracy
- Author
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Aiyi Liu, Mei-Ling Ting Lee, Larry Tang, Qizhai Li, and Wei Zhang
- Subjects
Statistics and Probability ,Matching (statistics) ,Biometry ,Biometrics ,Computer science ,01 natural sciences ,Stochastic ordering ,Article ,General Biochemistry, Genetics and Molecular Biology ,010104 statistics & probability ,03 medical and health sciences ,Computer Simulation ,0101 mathematics ,Algebraic expression ,Empirical process ,030304 developmental biology ,0303 health sciences ,Models, Statistical ,General Immunology and Microbiology ,Receiver operating characteristic ,business.industry ,Applied Mathematics ,Estimator ,Pattern recognition ,General Medicine ,Constraint (information theory) ,ROC Curve ,Area Under Curve ,Artificial intelligence ,General Agricultural and Biological Sciences ,business ,Biomarkers - Abstract
Receiver operating characteristic (ROC) curve is commonly used to evaluate and compare the accuracy of classification methods or markers. Estimating ROC curves has been an important problem in various fields including biometric recognition and diagnostic medicine. In real applications, classification markers are often developed under two or more ordered conditions, such that a natural stochastic ordering exists among the observations. Incorporating such a stochastic ordering into estimation can improve statistical efficiency (Davidov and Herman, 2012). In addition, clustered and correlated data arise when multiple measurements are gleaned from the same subject, making estimation of ROC curves complicated due to within-cluster correlations. In this article, we propose to model the ROC curve using a weighted empirical process to jointly account for the order constraint and within-cluster correlation structure. The algebraic properties of resulting summary statistics of the ROC curve such as its area and partial area are also studied. The algebraic expressions reduce to the ones by Davidov and Herman (2012) for independent observations. We derive asymptotic properties of the proposed order-restricted estimators and show that they have smaller mean-squared errors than the existing estimators. Simulation studies also demonstrate better performance of the newly proposed estimators over existing methods for finite samples. The proposed method is further exemplified with the fingerprint matching data from the National Institute of Standards and Technology Special Database 4.
- Published
- 2019
44. A model‐based approach for clustering of multivariate semicontinuous data with application to dietary pattern analysis and intervention
- Author
-
Aiyi Liu, Ya-hui Lu, Huimin Duan, Wei Zhang, and Tao Jiang
- Subjects
Statistics and Probability ,Multivariate statistics ,Epidemiology ,Inference ,Subgroup analysis ,Health Promotion ,01 natural sciences ,010104 statistics & probability ,03 medical and health sciences ,0302 clinical medicine ,Intervention (counseling) ,Expectation–maximization algorithm ,Statistics ,Cluster Analysis ,Humans ,Computer Simulation ,030212 general & internal medicine ,0101 mathematics ,Cluster analysis ,Mathematics ,Dietary pattern ,Mixture model ,Diet ,Binomial Distribution ,Multivariate Analysis ,Algorithms - Abstract
Semicontinuous data, characterized by a sizable number of zeros and observations from a continuous distribution, are frequently encountered in health research concerning food consumptions, physical activities, medical and pharmacy claims expenditures, and many others. In analyzing such semicontinuous data, it is imperative that the excessive zeros be adequately accounted for to obtain unbiased and efficient inference. Although many methods have been proposed in the literature for the modeling and analysis of semicontinuous data, little attention has been given to clustering of semicontinuous data to identify important patterns that could be indicative of certain health outcomes or intervention effects. We propose a Bernoulli-normal mixture model for clustering of multivariate semicontinuous data and demonstrate its accuracy as compared to the well-known clustering method with the conventional normal mixture model. The proposed method is illustrated with data from a dietary intervention trial to promote healthy eating behavior among children with type 1 diabetes. In the trial, certain diabetes friendly foods (eg, total fruit, whole fruit, dark green and orange vegetables and legumes, whole grain) were only consumed by a proportion of study participants, yielding excessive zero values due to nonconsumption of the foods. Baseline foods consumptions data in the trial are used to explore preintervention dietary patterns among study participants. While the conventional normal mixture model approach fails to do so, the proposed Bernoulli-normal mixture model approach has shown to be able to identify a dietary profile that significantly differentiates the intervention effects from others, as measured by the popular healthy eating index at the end of the trial.
- Published
- 2019
45. Younger age and early puberty are associated with cognitive function decline in children with Cushing disease
- Author
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Joo Young Kang, Aiyi Liu, Constantine A. Stratakis, Margaret F. Keil, Edythe Wiggs, and Deborah P. Merke
- Subjects
Adult ,medicine.medical_specialty ,Adolescent ,Endocrinology, Diabetes and Metabolism ,Trail Making Test ,Neuropsychological Tests ,Article ,Pubertal stage ,Endocrinology ,Cognition ,Internal medicine ,medicine ,Humans ,Prospective Studies ,Child ,Pituitary ACTH Hypersecretion ,California Verbal Learning Test ,Intelligence quotient ,business.industry ,Puberty ,Neuropsychology ,Wechsler Adult Intelligence Scale ,Wide Range Achievement Test ,business ,Clinical psychology - Abstract
Objective To investigate the effect of hypercortisolism on the developing brain we performed clinical, cognitive, and psychological evaluation of children with Cushing disease (CD) at diagnosis and 1 year after remission. Study design Prospective study of 41 children with CD. Children completed diverse sets of cognitive measures before and 1 year after remission. Neuropsychological evaluation included the Wechsler Intelligence Scale, California Verbal Learning Test, Trail Making Test, the combined subset scores of Wide Range Achievement Test and Woodcock-Johnson Psychoeducational Battery Test of Achievement, and the Behavioral Assessment System for Children. Results Comprehensive cognitive evaluations at baseline and 1 year following cure revealed significant decline mostly in nonverbal skills. Decrements occurred in most of the various indices that measure all aspects of cognitive function and younger age and early pubertal stage largely contributed to most of this decline. Results indicated that age at baseline was associated with positive regression weights for changes in scores for verbal, performance, and full intelligence quotient (IQ) scores and for subtests arithmetic, picture completion, coding, block design, scores; indicating that older age at baseline was associated with less of a deterioration in cognitive scores from pre- to posttreatment. Conclusion Our findings suggest that chronic glucocorticoid excess and accompanying secondary hormonal imbalances followed by eucortisolemia have detrimental effects on cognitive function in the developing brain; younger age and pubertal stage are risk factors for increased vulnerability, while older adolescents have cognitive vulnerabilities like that of adult patients affected with CD.
- Published
- 2021
46. Modifiable risk factors and long term risk of type 2 diabetes among individuals with a history of gestational diabetes mellitus: prospective cohort study
- Author
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Jiaxi Yang, Frank Qian, Jorge E Chavarro, Sylvia H Ley, Deirdre K Tobias, Edwina Yeung, Stefanie N Hinkle, Wei Bao, Mengying Li, Aiyi Liu, James L Mills, Qi Sun, Walter C Willett, Frank B Hu, and Cuilin Zhang
- Subjects
Diabetes, Gestational ,Diabetes Mellitus, Type 2 ,Pregnancy ,Risk Factors ,Humans ,Female ,Genetic Predisposition to Disease ,Obesity ,Prospective Studies ,General Medicine ,Overweight ,Body Mass Index - Abstract
ObjectivesTo evaluate the individual and combined associations of five modifiable risk factors with risk of type 2 diabetes among women with a history of gestational diabetes mellitus and examine whether these associations differ by obesity and genetic predisposition to type 2 diabetes.DesignProspective cohort study.SettingNurses’ Health Study II, US.Participants4275 women with a history of gestational diabetes mellitus, with repeated measurements of weight and lifestyle factors and followed up between 1991 and 2009.Main outcome measureSelf-reported, clinically diagnosed type 2 diabetes. Five modifiable risk factors were assessed, including not being overweight or obese (body mass index of the modified Alternate Healthy Eating Index), regular exercise (≥150 min/week of moderate intensity or ≥75 min/week of vigorous intensity), moderate alcohol consumption (5.0-14.9 g/day), and no current smoking. Genetic susceptibility for type 2 diabetes was characterised by a genetic risk score based on 59 single nucleotide polymorphisms associated with type 2 diabetes in a subset of participants (n=1372).ResultsOver a median 27.9 years of follow-up, 924 women developed type 2 diabetes. Compared with participants who did not have optimal levels of any of the risk factors for the development of type 2 diabetes, those who had optimal levels of all five factors had >90% lower risk of the disorder. Hazard ratios of type 2 diabetes for those with one, two, three, four, and five optimal levels of modifiable factors compared with none was 0.94 (95% confidence interval 0.59 to 1.49), 0.61 (0.38 to 0.96), 0.32 (0.20 to 0.51), 0.15 (0.09 to 0.26), and 0.08 (0.03 to 0.23), respectively (PtrendtrendConclusionsAmong women with a history of gestational diabetes mellitus, each additional optimal modifiable factor was associated with an incrementally lower risk of type 2 diabetes. These associations were seen even among individuals who were overweight/obese or were at greater genetic susceptibility.
- Published
- 2022
47. Self-compassion and posttraumatic growth mediate the relations between social support, prosocial behavior, and antisocial behavior among adolescents after the Ya'an earthquake
- Author
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Wenchao Wang, Aiyi Liu, and Xinchun Wu
- Subjects
050103 clinical psychology ,conducta antisocial ,animal structures ,反社会行为 ,RC435-571 ,Affect (psychology) ,Developmental psychology ,Social support ,03 medical and health sciences ,0302 clinical medicine ,0501 psychology and cognitive sciences ,Psychiatry ,antisocial behaviour ,Basic Research Article ,Posttraumatic growth ,05 social sciences ,亲社会行为 ,self-compassion ,030227 psychiatry ,apoyo social ,autocompasión ,Prosocial behavior ,社会支持 ,自我同情 ,prosocial behaviour ,Psychology ,Self-compassion ,Child behaviour ,PTG ,Research Article ,conducta prosocial - Abstract
Background: Previous studies indicate that social support, self-compassion, and posttraumatic growth (PTG) can affect prosocial behaviour and antisocial behaviour, but few studies have examined their combined role in prosocial and antisocial behaviour among adolescents who have experienced traumatic events. Objective: This study examined the mediating roles of self-compassion and PTG in the relationship between social support and prosocial and antisocial behaviour among Chinese adolescents after the Ya’an earthquake. Method: Four and a half years after the Ya’an earthquake, 492 students aged 13 to 18 in Lushan County (98.6% of the 499 students surveyed) were assessed using the following system: Measures of Trauma Exposure Questionnaire, Social Support Questionnaire, Self-Compassion Scale, Posttraumatic Growth Inventory, and Child Behaviour Problems Questionnaire. Results: When we controlled for gender, age, and traumatic exposure, social support had a positive effect on prosocial behaviour. Moreover, social support had an indirect and positive effect on prosocial behaviour via positive self-compassion and PTG, as well as via an indirect path from positive self-compassion to PTG, but social support had a negative effect on antisocial behaviour via PTG, as well as via an indirect path from positive self-compassion to PTG on antisocial behaviour. Social support also had a positive effect on antisocial behaviour via negative self-compassion. Conclusion: Findings suggest that increased support may be beneficial for prosocial behaviour and reduce antisocial behaviour. Self-compassion and PTG play a significant mediating role between social support, prosocial behaviour, and antisocial behaviour., HIGHLIGHTS • This study examined the mediating roles of self-compassion (positive and negative self-compassion) and PTG in the relationship between social support and prosocial and antisocial behavior among Chinese adolescents after the Ya’an earthquake.
- Published
- 2021
48. Nested Group Testing Procedure
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Wenjun Xiong, Juan Ding, Wei Zhang, Aiyi Liu, and Qizhai Li
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Statistics and Probability ,Computational Mathematics ,Applied Mathematics - Abstract
We investigated the false-negative, true-negative, false-positive, and true-positive predictive values from a general group testing procedure for a heterogeneous population. We show that its false (true)-negative predictive value of a specimen is larger (smaller), and the false (true)-positive predictive value is smaller (larger) than that from individual testing procedure, where the former is in aversion. Then we propose a nested group testing procedure, and show that it can keep the sterling characteristics and also improve the false-negative predictive values for a specimen, not larger than that from individual testing. These characteristics are studied from both theoretical and numerical points of view. The nested group testing procedure is better than individual testing on both false-positive and false-negative predictive values, while retains the efficiency as a basic characteristic of a group testing procedure. Applications to Dorfman's, Halving and Sterrett procedures are discussed. Results from extensive simulation studies and an application to malaria infection in microscopy-negative Malawian women exemplify the findings.
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- 2021
49. A prospective study of artificially sweetened beverage intake and cardiometabolic health among women at high risk
- Author
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Sylvia H. Ley, Mengying Li, Liwei Chen, Stefanie N. Hinkle, Jing Wu, James L. Mills, Louise G. Grunnet, Aiyi Liu, Cuilin Zhang, Yeyi Zhu, Anne A. Bjerregaard, Freja Bach Kampmann, Shristi Rawal, Mohammad L. Rahman, Sjurdur F. Olsen, and Thor I Halldorsson
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obesity ,Glycated Hemoglobin A ,nonnutritive sweeteners ,Denmark ,Medicine (miscellaneous) ,Medical and Health Sciences ,Body Mass Index ,Cohort Studies ,chemistry.chemical_compound ,Engineering ,0302 clinical medicine ,Pregnancy ,Risk Factors ,Clinical endpoint ,Prospective Studies ,030212 general & internal medicine ,Prospective cohort study ,artificially sweetened beverages ,Nutrition and Dietetics ,diabetes ,Obstetrics ,Gestational diabetes ,Original Research Communications ,Cardiovascular Diseases ,Gestational ,language ,Female ,gestational diabetes ,Type 2 ,cardiometabolic health ,Adult ,medicine.medical_specialty ,030209 endocrinology & metabolism ,Beverages ,Danish ,03 medical and health sciences ,SDG 3 - Good Health and Well-being ,Metabolic Diseases ,Diabetes mellitus ,Diabetes Mellitus ,medicine ,Humans ,Glycated Hemoglobin ,Nutrition & Dietetics ,business.industry ,soda ,medicine.disease ,Obesity ,language.human_language ,Diabetes, Gestational ,Diabetes Mellitus, Type 2 ,chemistry ,Sweetening Agents ,Women's Health ,Glycated hemoglobin ,diet ,business ,Follow-Up Studies - Abstract
Author(s): Hinkle, Stefanie N; Rawal, Shristi; Bjerregaard, Anne Ahrendt; Halldorsson, Thor I; Li, Mengying; Ley, Sylvia H; Wu, Jing; Zhu, Yeyi; Chen, Liwei; Liu, Aiyi; Grunnet, Louise Groth; Rahman, Mohammad L; Kampmann, Freja Bach; Mills, James L; Olsen, Sjurdur F; Zhang, Cuilin | Abstract: BackgroundArtificially sweetened beverages (ASBs) are commonly consumed and recommended for individuals at high risk for cardiometabolic diseases; however, the health effects of ASBs remain contradictory. Given that cross-sectional analyses are subject to reverse causation, prospective studies with long-term follow-up are needed to evaluate associations between ASBs and cardiometabolic health, especially among high-risk individuals.ObjectiveThe aim of this study was to examine associations of ASB intake and cardiometabolic health among high-risk women with prior gestational diabetes mellitus (GDM).MethodsWe included 607 women with GDM from the Danish National Birth Cohort (DNBC; 1996-2002) who completed a clinical exam 9-16 y after the DNBC pregnancy for the Diabetes a Women's Health (DWH) Study (2012-2014). We assessed ASB intake using FFQs completed during the DNBC pregnancy and at the DWH Study clinical exam. We examined cardiometabolic outcomes at the DWH clinical exam. We estimated percentage differences in continuous cardiometabolic markers and RRs for clinical endpoints in association with ASB intake both during pregnancy and at follow-up adjusted for prepregnancy BMI, diet, and lifestyle factors. Sensitivity analyses to account for reverse causation were performed.ResultsIn pregnancy and at follow-up, 30.4% and 36.4% of women regularly (≥2 servings/wk) consumed ASB, respectively. Consumption of ASBs, both during pregnancy and at follow-up, was associated with higher glycated hemoglobin (HbA1c), insulin, HOMA-IR, triglycerides, liver fat, and adiposity and with lower HDL at follow-up. After adjustment for covariates, particularly prepregnancy BMI, the majority of associations between ASB intake in pregnancy and outcomes at follow-up became null with the exception of HbA1c. ASB intake at follow-up (≥1 serving/d compared with l1 serving/mo) was associated with higher HbA1c (6.5%; 95% CI: 1.9, 11.3; P-trend = 0.007); however, associations were not upheld in sensitivity analyses for reverse causation.ConclusionsAmong Danish women with a history of GDM, ASB intake was not significantly associated with cardiometabolic profiles.
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- 2019
50. A cluster‐adjusted rank‐based test for a clinical trial concerning multiple endpoints with application to dietary intervention assessment
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Larry Tang, Wei Zhang, Qizhai Li, and Aiyi Liu
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Statistics and Probability ,Computer science ,01 natural sciences ,General Biochemistry, Genetics and Molecular Biology ,010104 statistics & probability ,03 medical and health sciences ,Intervention (counseling) ,Statistics ,Cluster Analysis ,Humans ,Intervention trial ,0101 mathematics ,030304 developmental biology ,Clinical Trials as Topic ,0303 health sciences ,Models, Statistical ,General Immunology and Microbiology ,Test procedures ,Applied Mathematics ,Rank (computer programming) ,General Medicine ,Diet ,Test (assessment) ,Clinical trial ,Data Interpretation, Statistical ,Multivariate test ,General Agricultural and Biological Sciences ,Biomarkers - Abstract
Multiple endpoints are often naturally clustered based on their scientific interpretations. Tests that compare these clustered outcomes between independent groups may lose efficiency if the cluster structures are not properly accounted for. For the two-sample generalized Behrens-Fisher hypothesis concerning multiple endpoints we propose a cluster-adjusted multivariate test procedure for the comparison and demonstrate its gain in efficiency over test procedures that ignore the clusters. Data from a dietary intervention trial are used to illustrate the methods.
- Published
- 2019
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