140 research outputs found

    The Numerical Study of Aeroacoustics Performance of Wings with Different Wavelength Leading-Edge Tubercles

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    The leading-edge tubercle is a type of airfoil modification that inspired by the humpback whale. It was found that the aerodynamic performance of the wing would increase compared to the wing without tubercles. In the past several years, a lot of numerical and experimental studies have been accomplished to explore this leading-edge modification. Besides the aerodynamic performance change, this research explores the aeroacoustics behavior of airfoils with leading-edge tubercles. A numerical study based on Computational Fluid Dynamics (CFD) is established, and simulations using Star CCM are accomplished based on reasonable set-ups. The airfoil chosen to create the wing is NACA 4412 which is an asymmetric airfoil. Two different tubercle wavelengths were used: 20 mm and 25 mm. The baseline airfoil is the wing that made of the same airfoil but without any modifications. For wings with leading-edge tubercles, the wavelength of the tubercles is the only changing parameter. It was found that the wings with leading-edge tubercles can reduce the noise generation, and the best noise reduction is achieved for a value of 2.525 dB (Decibel) at Point Receiver 10 for the wing that has 25 mm wavelength leading-edge tubercles. However, the wavelength of tubercles does not affect the aeroacoustics performance in an obvious way

    Prevalence and Associated Factors of Elder Mistreatment in a Rural Community in People's Republic of China: A Cross-Sectional Study

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    Background: Current knowledge about elder mistreatment is mainly derived from studies done in Western countries, which indicate that this problem is related to risk factors such as a shared living situation, social isolation, disease burden, and caregiver strain. We know little about prevalence and risk factors for elder mistreatment and mistreatment subtypes in rural China where the elder population is the most vulnerable. Methods: In 2010, we conducted a cross-sectional survey among older adults aged 60 or older in three rural communities in Macheng, a city in Hubei province, China. Of 2245 people initially identified, 2039 were available for interview and this was completed in 2000. A structured questionnaire was used to collect data regarding mistreatment and covariates. Logistic regression analysis was used to identify factors related to elder mistreatment and subtypes of mistreatment. Results: Elder mistreatment was reported by 36.2 % (95 % CI: 34.1%–38.3%) of the participants. Prevalence rates of psychological mistreatment, caregiver neglect, physical mistreatment, and financial mistreatment were 27.3 % (95 % CI

    Causal relationship between kidney stones and gut microbiota contributes to the gut-kidney axis: a two-sample Mendelian randomization study

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    BackgroundGut microbiota, particularly Oxalobacter formigenes, has been previously reported to be associated with kidney stones. However, the conflicting results from both observational and intervention studies have created substantial uncertainty regarding the contribution of Oxalobacter formigenes to the formation of kidney stone.MethodsWe employed a two-sample MR analysis to investigate the causal relationship between gut microbiota and kidney stones using GWASs summary statistics obtained from the MiBioGen and FinnGen consortia. Moreover, we conducted a reserve MR analysis to assess the direction of the causal associations between gut microbiota and kidney stones. The inverse variance weighted (IVW) approach represents the primary method of Mendelian Randomization (MR) analysis.ResultsOur analyses do not yield supportive evidence for a causal link between the genus Oxalobacter (OR = 0.99, 95% CI: 0.90–1.09, p = 0.811) and the formation of kidney stones. The order Actinomycetales (OR = 0.79, 95% CI: 0.65–0.96, p = 0.020), family Actinomycetaceae (OR = 0.79, 95% CI: 0.65–0.96, p = 0.019), family Clostridiaceae 1 (OR = 0.80, 95% CI: 0.67–0.96, p = 0.015), genus Clostridiumsensustricto 1 (OR = 0.81, 95% CI: 0.67–0.98, p = 0.030) and genus Hungatella (OR = 0.86, 95% CI: 0.74–0.99, p = 0.040) had protective effects on kidney stones, and the genus Haemophilus (OR = 1.16, 95% CI: 1.01–1.33, p = 0.032), genus Ruminococcaceae (UCG010) (OR = 1.38, 95% CI: 1.04–1.84, p = 0.028), genus Subdoligranulum (OR = 1.27, 95% CI: 1.06–1.52, p = 0.009) were risk factors for kidney stones. Differential abundance analysis provide no evidence of a association between Oxalobacter formigenes and kidney stones, and showed genus Subdoligranulum were risk factors for kidney stones. Reverse MR analysis did not indicate any causal association of kidney stones on gut microbiota. No considerable heterogeneity of instrumental variables or horizontal pleiotropy was observed.ConclusionOur two-sample MR study did not find any causal relationship between genus Oxalobacter and kidney stones. The association between gut microbiota and kidney stones does not solely depend on the presence of genus Oxalobacter/Oxalobacter formigenes. A more integrated approach using multiple omics platforms is needed to better understand the pathogenesis of kidney stones in the context of complex gene–environment interactions over time

    Factors Associated with Fathers’ Attendance in a Latino Family Obesity Prevention Program

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    Community-based programs may contribute to Latino pediatric obesity prevention; however, attendance remains low. This study aimed to identify factors associated with Latino father/male caregiver attendance in family-based adolescent obesity prevention programs conducted as part of a randomized controlled trial. The study used cross-sectional data from 137 fathers in the program, involving eight weekly sessions to improve their children’s energy balance-related behaviors. Evaluation data were collected at baseline and post-intervention. Fathers in a waitlisted control group attended sessions after post-intervention data collection. Attendance patterns were identified using cluster analysis: consistently high attendance (50% of fathers), declining attendance (19%), and non-attendance (31%) clusters. Multinomial logistic regression was used to examine associations between attendance patterns and variables. Compared to consistently high attendance, fathers in the non-attendance cluster were more likely to have been assigned to the control group (odds ratio [OR] = 7.86, p \u3c 0.001), tended to have lower household income (OR = 2.50, p = 0.098), and attended the program at a site where the program occurred weekdays (OR = 0.35, p = 0.094). Maintaining contact during waiting periods and providing sessions online or during weekends could reduce non-attendance by enhancing convenience for low-income fathers working multiple jobs

    Latino adolescent-father discrepancies in reporting activity parenting practices and associations with adolescents’ physical activity and screen time

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    Latino fathers may play important roles in adolescents’ physical activity and screen time. However, informant discrepancies regarding paternal activity parenting practices may challenge studies supporting evidence-based applications. This study examined Latino adolescent-father discrepancies in reporting paternal activity parenting practices, types of discrepancies by participant characteristics, and associations between discrepancy types and adolescents’ physical activity and screen time.https://doi.org/10.1186/s12889-020-8199-

    Lifestyle factors, serum parameters, metabolic comorbidities, and the risk of kidney stones: a Mendelian randomization study

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    Background and objectiveThe early identification of modifiable risk factors is important for preventing kidney stones but determining causal associations can be difficult with epidemiological data. We aimed to genetically assess the causality between modifiable factors (lifestyle factors, serum parameters, and metabolic comorbidities) and the risk of kidney stones. Additionally, we aimed to explore the causal impact of education on kidney stones and its potential mediating pathways.MethodsWe conducted a two-sample Mendelian randomization (MR) study to explore the causal association between 44 modifiable risk factors and kidney stones. The FinnGen dataset initially explored the causal relationship of risk factors with kidney stones and the UK Biobank dataset was used as the validation set. Then, a meta-analysis was conducted by combining discovery and validation datasets. We used two-step MR to assess potential mediators and their mediation proportions between education and kidney stones.ResultsThe combined results indicated that previous exposures may increase the risk of kidney stones, including sedentary behavior, urinary sodium, the urinary sodium/potassium ratio, the urinary sodium/creatinine ratio, serum calcium, 25-hydroxyvitamin D (25OHD), the estimated creatinine-based glomerular filtration rate (eGFRcrea), GFR estimated by serum cystatin C (eGFRcys), body mass index (BMI), waist circumference, type 2 diabetes mellitus (T2DM), fasting insulin, glycated hemoglobin, and hypertension. Coffee intake, plasma caffeine levels, educational attainment, and the urinary potassium/creatinine ratio may decrease the risk of kidney stones. Ranked by mediation proportion, the effect of education on the risk of kidney stones was mediated by five modifiable risk factors, including sedentary behavior (mediation proportion, 25.7%), smoking initiation (10.2%), BMI (8.2%), T2DM (5.8%), and waist circumference (3.2%).ConclusionThis study provides MR evidence supporting causal associations of many modifiable risk factors with kidney stones. Sedentary lifestyles, obesity, smoking, and T2DM are mediating factors in the causal relationship between educational attainment and kidney stones. Our results suggest more attention should be paid to these modifiable factors to prevent kidney stones

    Differences in reporting food insecurity and factors associated with differences among Latino fathers and mothers

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    Food security status has been assessed as a representative score for households; however, different members in the same household may perceive and report food insecurity differently. A high prevalence of food insecurity has been reported among Latino households, therefore understanding differences in reporting food insecurity by Latino father-mother dyads may improve accuracy of assessment and plans to address food insecurity. This study aimed to 1) determine demographic characteristics and/or food-related factors associated with perceptions of food security status among Latino father-mother dyads, and 2) identify factors associated with discordance in perceptions of food insecurity between dyads. Baseline data were used from a community-based, youth obesity prevention program among Latino families (n = 106 father-mother dyads). Food security was assessed with a 2-item food insecurity screen. Logistic regression models were used to evaluate associations between reporting food security status and predictor variables for fathers, mothers, and dyad-discordant responses. Food insecurity was reported by 39% of fathers and 55% of mothers. Adjusted odds of reporting food insecurity were significantly higher for fathers perceiving their neighborhood was unsafe vs. safe (OR: 3.7, p < 0.05) and reporting lower vs. higher household income (OR: 3.2, p < 0.05). Adjusted odds of reporting food insecurity were significantly higher for mothers perceiving their neighborhood was unsafe vs. safe (OR: 4.1, p < 0.01) and reporting lower vs. higher home availability of fruit and vegetable (OR: 5.5, p < 0.01). Dyad discordance in reporting food security status occurred in 24% of the dyads. Adjusted odds of dyad discordant reports of food insecurity status were significantly higher for dyads reporting discordant responses regarding previous nutrition education (OR: 3.4, p < 0.05) and higher home fruit and vegetable accessibility (OR: 3.1, p < 0.05) compared to dyads reporting concordant responses. Among the 28 dyads who reported discordant nutrition education participation, 21 reported that fathers had never participated but mothers had participated more than once. Differential factors were associated with reporting food security among Latino father-mother dyads. Nutrition education for fathers that improves awareness of home food supplies and a better understanding of how food accessibility influences maternal perceptions may improve dyad discordance in reporting household food security.https://doi.org/10.1186/s12889-021-10971-

    Exposure to arsenic during pregnancy and newborn mitochondrial DNA copy number: A birth cohort study in Wuhan, China

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    This is an accepted manuscript of an article published by Elsevier in Chemosphere on 11/11/2019, available online: https://www.sciencedirect.com/science/article/abs/pii/S0045653519325755?via%3Dihub The accepted version of the publication may differ from the final published version.Background: Arsenic (As) is a widely distributed environmental chemical with potentially different toxicities. However, little is known about the impact of maternal As exposure on newborn mitochondrial DNA copy number (mtDNAcn), which may lie on the pathway linking As exposure to adverse health impacts. Objectives: We aimed to explore whether maternal As exposure was associated with newborn mtDNAcn. Methods: We conducted a birth cohort study of 762 mother-infant pairs in Wuhan, China, 2013-2015. Cord blood mtDNAcn was determined using qPCR. Maternal urinary As levels in each trimester were quantified by ICP-MS. Multiple informant models were used to examine the associations of repeated urinary As levels with cord blood mtDNAcn. Results: The median urinary As levels in the first, second, and third trimesters were 17.2 g/L, 16.0 g/L and 17.0 g/L respectively. In the multivariate model, each doubling increase in the first-trimester urinary As level was associated with a 6.6% (95% CI: -12.4%, -0.5%) decrease in cord blood mtDNAcn. The highest versus lowest quintile of first-trimester urinary As level was related to a 19.0% (95% CI: -32.9%, -2.2%) lower cord blood mtDNAcn. There was significant association of urinary As levels in the second and third trimesters with cord blood mtDNAcn. The inverse relationship between first-trimester urinary As level and cord blood mtDNAcn was more pronounced among female infants. Conclusions: First-trimester As exposure was associated with decreased cord blood mtDNAcn. The potential health impacts of decreased mtDNAcn in early life need to be further clarified
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