bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical simulation of the blade channel vortices in a Francis turbine runner
Authors: Zhou Lingjiu , Liu Meng , Wang Zhengwei , Liu Demin , Zhao Yongzhi
Published: June 2017

Purpose

This study analyzes the blade channel vortices inside Francis runner with a particular focus on the identification of different types of vortices and their causes.

Design/methodology/approach

A single-flow passage of the Francis runner with refined mesh and periodic boundary conditions was used for the numerical simulation to reduce the computational resource. The steady-state Reynolds-averaged Navier–Stokes equations closed with the k-ω shear–stress transport (SST) turbulence model were solved by ANSYS CFX to determine the flow field. The vortices were identified by the second largest eigenvalue of velocity.

Findings

Four types of vortices were identified inside the runner. Three types were related to the inlet flow. The last one (Type 4) was caused by the reversed flow near the runner crown and had the lowest pressure inside the core near the runner outlet. Thus, in the blade channel vortex inception line, Type 4 vortex would appear earlier than the other three ones. Besides, the Type 4 vortex emerged from the crown and shed toward the blade-trailing edge. And its location moved from near the crown down to near the band when the unit speed increased or unit discharge decreased.

Research limitations/implications

Although the refined mesh was used and the main vortices in the Francis runner were well predicted, the current mesh is not enough to accurately predict the lowest pressure in the channel vortex core.

Practical/implications

This knowledge is instructive in the runner blade design and troubleshooting related to the channel vortex.

Originality/value

This study gives an overview of the main observed blade channel vortices and their causes, and points out the important role the reversed flow plays in the formation of blade channel vortices. This knowledge is instructive in the runner blade design and troubleshooting related to blade channel vortices.
Shooting homotopy analysis method
Authors: Ahmad Soltani L. , Shivanian E. , Ezzati Reza
Published: June 2017

Purpose

The purpose of this paper is to present a new method based on the homotopy analysis method (HAM) with the aim of fast searching and calculating multiple solutions of nonlinear boundary value problems (NBVPs).

Design/methodology/approach

A major problem with the previously modified HAM, namely, predictor homotopy analysis method, which is used to predict multiplicity of solutions of NBVPs, is a time-consuming computation of high-order HAM-approximate solutions due to a symbolic variable namely “prescribed parameter”. The proposed new technique which is based on traditional shooting method, and the HAM cuts the dependency on the prescribed parameter.

Findings

To demonstrate the computational efficiency, the mentioned method is implemented on three important nonlinear exactly solvable differential equations, namely, the nonlinear MHD Jeffery–Hamel flow problem, the nonlinear boundary value problem arising in heat transfer and the strongly nonlinear Bratu problem.

Originality/value

The more high-order approximate solutions are computable, multiple solutions are easily searched and discovered and the more accurate solutions can be obtained depending on how nonhomogeneous boundary conditions are transcribed to the homogeneous boundary conditions.
A Krylov enhanced proper orthogonal decomposition method for frequency domain model reduction
Authors: Binion David , Chen Xiaolin
Published: June 2017

Purpose

This paper aims to describe a method for efficient frequency domain model order reduction. The method attempts to combine the desirable attributes of Krylov reduction and proper orthogonal decomposition (POD) and is entitled Krylov enhanced POD (KPOD).

Design/methodology/approach

The KPOD method couples Krylov’s moment-matching property with POD’s data generalization ability to construct reduced models capable of maintaining accuracy over wide frequency ranges. The method is based on generating a sequence of state- and frequency-dependent Krylov subspaces and then applying POD to extract a single basis that generalizes the sequence of Krylov bases.

Findings

The frequency response of a pre-stressed microelectromechanical system resonator is used as an example to demonstrate KPOD’s ability in frequency domain model reduction, with KPOD exhibiting a 44 per cent efficiency improvement over POD.

Originality/value

The results indicate that KPOD greatly outperforms POD in accuracy and efficiency, making the proposed method a potential asset in the design of frequency-selective applications.
Low-order mixed finite element analysis of progressive failure in pressure-dependent materials within the framework of the Cosserat continuum
Authors: Tang Hongxiang , Guan Yuhui , Zhang Xue , Zou Degao
Published: June 2017

Purpose

This paper aims to develop a finite element analysis strategy, which is suitable for the analysis of progressive failure that occurs in pressure-dependent materials in practical engineering problems.

Design/methodology/approach

The numerical difficulties stemming from the strain-softening behaviour of the frictional material, which is represented by a non-associated Drucker–Prager material model, is tackled using the Cosserat continuum theory, while the mixed finite element formulation based on Hu–Washizu variational principle is adopted to allow the utilization of low-order finite elements.

Findings

The effectiveness and robustness of the low-order finite element are verified, and the simulation for a real-world landslide which occurred at the upstream side of Carsington embankment in Derbyshire reconfirms the advantages of the developed elastoplastic Cosserat continuum scheme in capturing the entire progressive failure process when the strain-softening and the non-associated plastic law are involved.

Originality/value

The permit of using low-order finite elements is of great importance to enhance computational efficiency for analysing large-scale engineering problems. The case study reconfirms the advantages of the developed elastoplastic Cosserat continuum scheme in capturing the entire progressive failure process when the strain-softening and the non-associated plastic law are involved.
Numerical and experimental investigation on influence of compound dimple on tribological performances for rough parallel surfaces
Authors: Meng Fanming , Cheng Zhitao , Zou Tiangang
Published: June 2017

Purpose

This study aims to explore the superiority of the compound dimple (e.g. the rectangular-rectangular dimple) and compare its tribological performance for rough parallel surfaces with those of the traditional one-layer dimple (simple dimple).

Design/methodology/approach

A mixed-lubrication model for a rough textured surface is established and solved using the finite difference method for film pressure and contact pressure. To accelerate the evaluation of surface deformation, the efficient Continuous convolution fast Fourier transform algorithm is applied. The effects of the compound dimple on the tribological performance for the rough parallel surfaces is numerically investigated. And these effects are compared with those of the simple dimple. Furthermore, a reciprocating friction test is conducted to verify the superiority of the compound dimple.

Findings

The compound dimple exhibits better tribological performances in comparison with the traditional simple dimple, that is, a larger load-carrying capacity and a smaller friction coefficient. To achieve the best tribological performances for the rough parallel surfaces, the depth ratio of the lower pore to the total pore of the compound dimple and the dimple interval should be reasonably chosen. For the surface with compound dimples, there exists an optimal surface roughness to simultaneously maximize the load-carrying capacity and minimize the friction coefficient. The smaller friction coefficient of the surface with compound dimples is verified by the reciprocating friction test.

Originality/value

The compound dimple is proposed and the superiority of this novel surface texture is confirmed. This study is expected to provide a new texturing method to improve the tribological performances of the traditional simple dimple.
Effects of surface roughness and porous structure on the hydrodynamic lubrication of multi-layer oil bearing
Authors: Zhang Guotao , Yin Yanguo , Xue Lu , Zhu Guoqian , Tian Ming
Published: June 2017

Purpose

The purpose of this paper is to discuss the combined effects of the deterministic surface roughness and porous structure on the lubrication property of the multi-layer bearing.

Design/methodology/approach

Digital filtering technique and Kozeny-Carman equation are used to simulate the random Gauss surface and the internal pore structure of the porous bearing, respectively. Effects of surface morphology, structure and pores on the lubrication property are discussed by using the finite difference method.

Findings

Results show that the lubrication performance of the multi-layer bearing increased with the increase of the surface roughness. Also, the transverse surface is better than that of the longitudinal surface. Moreover, lubricating property is getting worse with the increase of the height of each layer and the porosity. The lower permeability surface is beneficial to improve the lubrication performance when the total porosity is certain.

Originality/value

The effect of the Gauss roughness parameters on the detail of lubrication performance are analysed, such as the migration of the oil film rupture point position, the expansion of the pressure distribution region and the fluctuation of the pressure distribution curve with the roughness parameters. The combined effects of surface roughness, multi-layer structure and the internal pore parameters on the hydrodynamic behaviours of multi-layer porous bearing are analysed. This work is beneficial for the analysis of the tribological property and the structural design of multi-layer bearing.
Experimental-numerical analysis of contact conditions influence on the ironing strip drawing process
Authors: Djordjević Milan , Mandić Vesna , Aleksandrović Srbislav , Lazić Vukić , Arsić Dušan , Nikolić Ružica R. , Gulišija Zvonko
Published: June 2017

Purpose

The purpose of this paper is comparison of experimental values of the drawing forces to numerical values in different contact conditions, taking into account the appearance of galling which occurs due to of difficult drawing process conditions.

Design/methodology/approach

The following two research approaches are used in this paper – the physical modeling, realized by the laboratory experiment, and the numerical simulation of the ironing drawing process. By analyzing the obtained results, the technique of physical modeling, with help of the laboratory equipment and numerical simulation by application of the finite element method, can be successfully used in studying the thin sheet ironing – strip drawing process.

Findings

It is significant to compare values of the deformation forces obtained by physical experiment to values obtained by the numerical simulation. In that way, it is possible to compare applied contact conditions (four lubricants in that case) and estimate matching of experimentally and numerically obtained results of the deformation forces. Presented results point out very good technological characteristics of ecologically friendly lubricant (single-bath) and grease based on MoS2. Significant decrease of the deformation force was achieved by its application, as well as maintaining of the lubricant’s layer during the forming process and almost complete elimination of galling on the contact.

Practical implications

Numerical analysis of stresses in the working piece wall, during the thin sheet strip drawing, requires precise values of the friction coefficient. It is an important indicator because one can define the contact conditions as the input data for the numerical simulation, based on its values for each type of lubricants and each value of the compressive lateral force.

Originality/value

The environmentally friendly lubricant tested exhibits a more favorable distribution of the drawing force during the process, mainly in experimental case. Grease based on MoS2 has good lubricating properties but that lubricant is conventional and environmentally unacceptable. Ecologically friendly lubricant can be successfully used in real ironing strip drawing process especially for high values of holding force achieving an increased tool life.
Contribution of roughness parameters in the scuffing performance of metallic surfaces
Authors: Wojciechowski Lukasz , Majchrowski Radomir , Mathia Thomas G.
Published: June 2017

Purpose

Boundary lubrication cannot provide long-term protection against scuffing. Therefore, it is fundamental to recognise the breaking point of the boundary layer that activates scuffing. Based on this assumption, three-dimensional (3D) morphologies of surfaces were characterised, and the fundamental conditions of the scuffing process were investigated to identify the transition from boundary lubrication conditions to catastrophic wear.

Design/methodology/approach

A series of systematic tribological double-blind experiments were carried out using a poorly lubricated cylinder/plane interface to model the tribological inverse problem in a boundary lubrication situation. Areal morphological analysis was performed, with the help of an optical interferometer, on a millimetric area corresponding to the contact surface during experimental tribological investigations. The statistical correlation between scuffing and the selected morphological parameters was evaluated. This evaluation study consisted of determining the linear, logarithmic, exponential, polynomial (of degree 2) or power dependency between time to scuffing and morphological parameters.

Findings

A clear, statistically confirmed relationship was observed between selected morphological parameters of the surface (Spd, Sha, Str, Sz) and its scuffing performance.

Originality/value

3D morphological parameters that best specified the technological scuffing performance of metallic surfaces were selected and proposed.
Influence of feed per tooth on tool wear based on 3D finite element simulation in micro-milling of Inconel 718
Authors: Lu Xiaohong , Wang FuRui , Jia Zhenyuan , Si Likun , Weng Yongqiang
Published: June 2017

Purpose

This paper aims to predict tool wear and reveal the relationship between feed per tooth and tool wear in micro-milling Inconel 718 process.

Design/methodology/approach

To study and solve the tool wear problem in micro-milling of Inconel 718 micro components, in this paper, the investigation of micro-milling Inconel 718 process was implemented based on DEFORM finite element simulation, and tool wear depth of micro-milling cutter acted as output.

Findings

Different from the traditional macro milling process, diameter reduction percentage and average flank wear length decreased with the increase of feed per tooth; tool wear depth decreased when the feed per tooth was less than the minimum chip thickness.

Originality/value

At present, research on the prediction of tool wear in micro-milling of Inconel 718 has never been publicly reported. This study is significant to reveal the relationship between cutting parameters (feed per tooth) and tool wear in micro-milling Inconel 718.
Analysis on grease lubrication properties of the tripod sliding universal coupling in automotive transmission shaft
Authors: Zhou Ye , Chang Degong , Li Songmei
Published: June 2017

Purpose

This paper aims to investigate the grease isothermal lubrication properties of the tripod sliding universal coupling (TSUC) in automotive transmission shaft and study its impact on a variety of factors to improve its grease lubrication properties.

Design/methodology/approach

Based on the simplified geometrical model, the research of grease lubrication properties of the TSUC was analyzed, and compared with oil lubrication in same parameters. Then the effects of effective radius, frequency (vehicle speed) and amplitude (angle between intermediate shaft and input shaft) on grease isothermal lubrication properties are theoretically investigated by using multigrid methods.

Findings

The results indicate that the grease isothermal elastohydrodynamic lubrication (EHL) film thickness shape and pressure distribution shape of the TSUC are similar to the oil lubrication, but the film thickness of grease lubrication is less than that of oil lubrication. Higher effective radius results in a wider pressure distribution, a lower center pressure and a thicker lubricating film. Higher frequency (vehicle speed) results in a remarkable second pressure peak and a thicker lubricating film. The effects of amplitude (angle between intermediate shaft and input shaft) and frequency have similar tendencies.

Originality/value

The numerical analysis research on grease lubrication properties of the TSUC is significant because the automotive transmission shaft is widely used. And it provides a new direction in designing TSUCs.
Climate warming as a driver of tundra shrubline advance
Authors: Myers‐Smith Isla H. , Hik David S.
Published: June 2017

Climate warming is predicted to alter ecological boundaries in high‐latitude ecosystems including the elevational or latitudinal extent of tall shrubs in Arctic and alpine tundra. Over 60 studies from 128 locations around the tundra biome have investigated shrub expansion in tundra ecosystems; however, only six studies test whether shrublines are actually advancing up hill‐slopes or northward into tundra where tall shrubs are currently absent.

We test the hypothesis that willow shrublines have expanded to higher elevations in relation to climate across a 50 × 50 km area in the Kluane Region of the southwest Yukon Territory, Canada by surveying of 379 shrubs at 14 sites and sampling of 297 of the surveyed shrubs at 10 sites. We compared growth and recruitment to climate variables to test the climate sensitivity of shrub increase using annual radial growth analysis, age distributions and repeat field surveys to estimate the current rate of shrubline advance.

We found consistent and increasing rates of recruitment of alpine willows, with estimates of faster advancing shrublines on shallower hill‐slopes. Mortality was extremely low across the elevation gradient. Aspect, elevation and species identity did not explain variation in recruitment patterns, suggesting a regional factor, such as climate, as the driver of the observed shrubline advance.

Annual radial growth of willows was best explained by variation in summer temperatures, and recruitment pulses by winter temperatures. Measured recruitment rates are ~20 ± 5 individuals per hectare per decade (M ± SE) and measured rates of increased shrub cover of ~5 ± 1% per decade (M ± SE) measured at the Pika Camp site between field surveys in 2009 and 2013. Our results suggest that shrubline will continue to advance over the next 50 years, if growing conditions remain suitable. However, if future conditions differ between summer and winter seasons, this could lead to contrasting trajectories for recruitment vs. growth, and influence the vegetation change observed on the landscape.

Synthesis. Our findings in the context of a review of the existing literature indicate that elevational and latitudinal shrublines, like treelines, are advancing in response to climate warming; however, the trajectories of change will depend on the climate drivers controlling recruitment vs. growth.
Measuring Economic Uncertainty and Its Effects
Authors: Moore Angus
Published: June 2017

I construct a monthly index of economic uncertainty for Australia. Economic uncertainty rose to historically high levels during the financial crisis and remained elevated until late 2013. The index is: higher around recessions, elections, monetary policy surprises and some major events; tends to increase faster than it decreases; and is driven by both domestic and foreign factors. I use the index to assess how uncertainty affects the Australian economy. Consistent with the ‘real options’ channel of uncertainty, I find that it reduces investment and employment growth. Similarly, uncertainty raises the household saving ratio, consistent with the ‘precautionary savings’ channel.
Just sick of it? Health and political trust in Western Europe
Authors: MATTILA MIKKO , RAPELI LAURI
Published: June 2017

This article explores two theoretical possibilities for why personal health may affect political trust: the psychological‐democratic contract theory, and the role of personal experience in opinion formation. It argues that citizens with health impairments are more likely to experience the direct effects of political decisions as they are more dependent on public health services. Negative subjective evaluations of public services can lower trust levels, especially if people's expectations are high. Using European Social Survey data, the association between health and trust in 19 Western European states is analysed. The results indicate that people in poor health exhibit lower levels of trust towards the political system than people in good health. The differences in trust between those in good and poor health are accentuated among citizens with left‐leaning ideological values. The results suggest that welfare issues may constitute a rare context in which personal, rather than collective, experiences affect opinion formation.
Feasibility of Canine Detection of Mass Storage Devices: A Study of Volatile Organic Compounds Emanating from Electronic Devices Using Solid Phase Microextraction
Authors: DeGreeff Lauryn E. , Cerreta Michelle , Rispoli Mark
Published: June 2017

Detection of canines are well‐known to be valuable in the location of contraband, such as explosives or narcotics. More recently, canines have been trained and utilized in the detection of concealed mass storage devices that might contain evidence of illegal activity such as child pornography. To lay the analytical foundation for this detection work, research was carried out to determine the volatile organic compounds associated with mass storage devices (MSD) that could be used by trained canines for detection. Headspace analysis of a variety of electronic devices was performed using solid phase microextraction (SPME) with gas chromatography/mass spectrometry (GC/MS). Analyses found several volatile compounds common to SIM and SD cards, as well as USB drives, including 2‐propenenitrile, styrene, isophorone, hydroxycyclohexyl phenyl ketone, and 2‐furanmethanol, tetrahydro. Results indicated that mass storage devices do have a characteristic odor profile making detection with minimal false alerts feasible for trained canines.
Farm to Sensory Lab: Taste of Blueberry Fruit by Children and Adults
Authors: Mennella Julie A. , Colquhoun Thomas A. , Bobowski Nuala K. , Olmstead James W. , Bartoshuk Linda , Clark Dave
Published: June 2017

The average American child eats fewer fruits than recommended. Although taste is the primary motivator for food intake among children, little research has systematically measured children's liking of fruit and determined whether their preferences differ from adults. We phenotyped 49 children and their mothers to determine: (1) their liking of the taste of 3 blueberry cultivars (“Arcadia,” “Keecrisp,” and “Kestrel”) from 2 harvests for which total soluble solids were determined using a handheld Brix refractometer; (2) the association between liking and blueberry sugar content; and (3) the most preferred level of fructose, one of the primary sugars in blueberry fruit. Multiple methods, identical for all participants, assessed which cultivar they liked best. Dietary intake, determined via 24‐h dietary recall, revealed most children (73%) and adults (92%) did not meet dietary guidelines for fruit intake. We found that during the 1st harvest, Keecrisp was sweeter by 4° Brix than either Arcadia or Kestrel and was the cultivar most preferred by both children and adults. For the 2nd harvest, mothers liked each of the cultivars equally, but children preferred Arcadia, which was 2° Brix sweeter than the other 2 cultivars. Like other sugars, children's most preferred concentration of fructose was significantly higher than that of adults. In sum, children appear to be more sensitive to smaller variations in sweetness than are adults. Identifying drivers of fruit preference and assessing children's liking for whole fruits are important steps in developing strategies to increase fruit consumption among children.
Comparison of Nutritional Composition, Aroma Compounds, and Biological Activities of Two Kinds of Tartary Buckwheat Tea
Authors: Guo Huimin , Yang Xiushi , Zhou Haitao , Luo Xiuxiu , Qin Peiyou , Li Jincai , Ren Guixing
Published: June 2017

Tartary buckwheat tea (TBT) is becoming increasingly popular for its unique flavor and health benefits. However, there is little information regarding the differences in nutritional quality among different kinds of TBT. Two kinds of TBT samples, whole grain tea (WGT) and whole plant tea (WPT), were collected from markets in China. The content of their nutritional compositions, including protein, amino acids, starch, fat, fatty acids, and flavonoids, as well as aroma compounds, were determined. Antioxidant and α‐glucosidase inhibitory activities were also evaluated. WPT showed higher levels of protein and fat relative to WGT, but the content of essential amino acids and fatty acids was lower. WPT contained more total flavonoids with quercetin as the predominant flavonoid (81%), while rutin was the principal flavonoid compound (86%) in WGT. GC‐MS analysis indicated that there were some differences in the aroma compound profile between WGT and WPT, though 14 aroma compounds were identified in both of them with 3‐ethyl‐2,5‐dimethyl‐pyrazine as the predominant compound. In addition, WPT showed superior antioxidant and α‐glucosidase inhibitory activities than WGT. However, the total flavonoid content determined in tea soup was decreased by 60% and 98% compared with that in the alcohol extracts of WGT and WPT, respectively. The antioxidant and α‐glucosidase inhibitory activities of tea soup were also lowered, especially for WPT. The differences between 2 kinds of TBT might be due to the variety of raw materials and processing methods. Diversified plant materials and scientific processing technologies should be taken into account to develop a nutritional and healthy TBT product.
Lupus in the far east: a modern epidemic
Authors: Li Philip H. , Lau Chak‐Sing
Published: June 2017

Systemic lupus erythematosus (SLE) is a diverse and heterogeneous disease with much variation between different ethnicities. Although more severe and prevalent in non‐Caucasian populations, the bulk of evidence regarding ‘Asian lupus’ had traditionally been extrapolated from studies on patient minorities in the West. Lupus research in Asia has since grown exponentially and now takes a leading role in improving the care for SLE patients worldwide. With recent advances, particularly from studies in population‐specific phenotyping, genome‐wide association studies, lupus nephritis and innovative treatment modalities, we now have an expanding understanding of both the basic science and clinical management of SLE. Upcoming breakthroughs from growing multi‐ethnic cohorts and international collaborations will likely bring further important ramifications for SLE management in the near future.
Prognostic model for brain metastases from lung adenocarcinoma identified with epidermal growth factor receptor mutation status
Authors: Li Hongwei , Wang Weili , Jia Haixia , Lian Jianhong , Cao Jianzhong , Zhang Xiaqin , Song Xing , Jia Sufang , Li Zhengran , Cao Xing , Zhou Wei , Han Songye , Yang Weihua , Xi Yanfen , Lian Shenming
Published: June 2017

Background

Several indices have been developed to predict survival of brain metastases (BM) based on prognostic factors. However, such models were designed for general brain metastases from different kinds of cancers, and prognostic factors vary between cancers and histological subtypes. Recently, studies have indicated that epidermal growth factor receptor (EGFR) mutation status may be a potential prognostic biological factor in BM from lung adenocarcinoma. Thus, we sought to define the role of EGFR mutation in prognoses and introduce a prognostic model specific for BM from lung adenocarcinoma.

Methods

Data of 256 patients with BM from lung adenocarcinoma identified with EGFR mutations were collected. Independent prognostic factors were confirmed using a Cox regression model. The new prognostic model was developed based on the results of multivariable analyses. The score of each factor was calculated by six‐month survival. Prognostic groups were divided into low, medium, and high risk based on the total scores. The prediction ability of the new model was compared to the three existing models.

Results

EGFR mutation and Karnofsky performance status were independent prognostic factors and were thus integrated into the new prognostic model. The new model was superior to the three other scoring systems regarding the prediction of three, six, and 12‐month survival by pairwise comparison of the area under the curve.

Conclusion

Our proposed prognostic model specific for BM from lung adenocarcinoma incorporating EGFR mutation status was valid in predicting patient survival. Further verification is warranted, with prospective testing using large sample sizes.
Cross‐sectional relations of whole‐blood miRNA expression levels and hand grip strength in a community sample
Authors: Murabito Joanne M. , Rong Jian , Lunetta Kathryn L. , Huan Tianxiao , Lin Honghuang , Zhao Qiang , Freedman Jane E. , Tanriverdi Kahraman , Levy Daniel , Larson Martin G.
Published: June 2017

MicroRNAs (miRNAs) regulate gene expression with emerging data suggesting miRNAs play a role in skeletal muscle biology. We sought to examine the association of miRNAs with grip strength in a community‐based sample. Framingham Heart Study Offspring and Generation 3 participants (n = 5668 54% women, mean age 55 years, range 24, 90 years) underwent grip strength measurement and miRNA profiling using whole blood from fasting morning samples. Linear mixed‐effects regression modeling of grip strength (kg) versus continuous miRNA ‘Cq’ values and versus binary miRNA expression was performed. We conducted an integrative miRNA–mRNA coexpression analysis and examined the enrichment of biologic pathways for the top miRNAs associated with grip strength. Grip strength was lower in women than in men and declined with age with a mean 44.7 (10.0) kg in men and 26.5 (6.3) kg in women. Among 299 miRNAs interrogated for association with grip strength, 93 (31%) had FDR q value < 0.05, 54 (18%) had an FDR q value < 0.01, and 15 (5%) had FDR q value < 0.001. For almost all miRNA–grip strength associations, increasing miRNA concentration is associated with increasing grip strength. miR‐20a‐5p (FDR q 1.8 × 10−6) had the most significant association and several among the top 15 miRNAs had links to skeletal muscle including miR‐126‐3p, miR‐30a‐5p, and miR‐30d‐5p. The top associated biologic pathways included metabolism, chemokine signaling, and ubiquitin‐mediated proteolysis. Our comprehensive assessment in a community‐based sample of miRNAs in blood associated with grip strength provides a framework to further our understanding of the biology of muscle strength.
A post‐GWAS confirming GPAT3 gene associated with pig growth and a significant SNP influencing its promoter activity
Authors: Wang Kejun , Liu Yufang , Xu Qiao , Liu Chengkun , Wang Jve , Ding Cui , Fang Meiying
Published: June 2017

Our previous genome‐wide association study revealed that a SNP, ASGA0040372, located upstream of glycerol‐3‐phosphate acyltransferase 3 (GPAT3), is related to growth traits in Duroc pigs. In this study, we aimed to extensively investigate the genetic variation of GPAT3 and to further verify the contribution of ASGA0040372 to growth traits and its effect on promoter activity. Our data, obtained based on gene cloning and rapid amplification of cDNA ends experiments, showed that there are 14 exons and three alternative splicing variants. Five SNPs were detected, including ASGA0040372 and four novel SNPs. Furthermore, the five SNPs obtained were used to confirm their genetic effects on pig growth by an association study in a Duroc pig population. The results indicated that three SNPs (ASGA0040372, RS331766122 and RS346215414) are highly associated with average daily gain or days to 100 kg traits (P‐value < 0.05). Subsequent analysis suggested that the promoter region of GPAT3 gene, from –950 to –500 bp, exhibited the highest activity. We also observed that ASGA0040372 (A/G) alleles have significantly different effects on promoter transcriptional activities, which leads to differential expression of GPAT3. Taken together, we conclude that the GPAT3 gene is associated with pig growth and that ASGA0040372 influences promoter activity of GPAT3 in pig.
A Complete Association of an intronic SNP rs6798742 with Origin of Spinocerebellar Ataxia Type 7‐CAG Expansion Loci in the Indian and Mexican Population
Authors: Faruq Mohammed , Magaña Jonathan J. , Suroliya Varun , Narang Ankita , Murillo‐Melo Nadia M. , Hernández‐Hernández Oscar , Srivastava Achal K. , Mukerji Mitali
Published: June 2017

Spinocerebellar ataxia type 7 (SCA7) is a rare neurogenetic disorder caused by highly unstable CAG repeat expansion mutation in coding region of SCA7. We aimed to understand the effect of diverse ATXN7 cis‐element in correlation with CAG expansion mutation of SCA7. We initially performed an analysis to identify the haplotype background of CAG expanded alleles using eight bi‐allelic single nucleotide polymorphisms (SNPs) flanking an ATXN7‐CAG expansion in 32 individuals from nine unrelated Indian SCA7 families and 88 healthy controls. Subsequent validation of the findings was performed in 89 ATXN7‐CAG mutation carriers and in 119 unrelated healthy controls of Mexican ancestry. The haplotype analyses showed a shared haplotype background and C allele of SNP rs6798742 (approximately 6 kb from the 3′‐end of CAG repeats) is in complete association with expanded, premutation, intermediate, and the majority of large normal (≥12) CAG allele. The C allele (ancestral/chimp allele) association was validated in SCA7 subjects and healthy controls from Mexico, suggesting its substantial association with CAG expanded and expansion‐prone chromosomes. Analysis of rs6798742 and other neighboring functional SNPs within 6 kb in experimental datasets (Encyclopedia of DNA Elements; ENCODE) shows functional marks that could affect transcription as well as histone methylation. An allelic association of the CAG region to an intronic SNP in two different ethnic and geographical populations suggests a ‐cis factor‐dependent mechanism in ATXN7 CAG‐region expansion.
Elevated anti‐Mullerian hormone in lean women may not indicate polycystic ovarian syndrome
Authors: Bradbury Rachel A. , Lee Paul , Smith Howard C.
Published: June 2017

Background

Polycystic ovarian syndrome (PCOS) is a heterogeneous disorder with clinical features shared with functional hypogonadotrophic hypogonadism (FHH).

Aim

To investigate the usefulness of an elevated (>40 pmol/L) anti‐Mullerian hormone (AMH) in identifying PCOS and distinguishing PCOS from FHH.

Materials and methods

141 patients with an elevated AMH and body mass index either <20 kg/m2 (lean) or >30 kg/m2 (obese) were selected and three subgroups analysed – obese, lean, lean with suspected FHH. FHH was diagnosed clinically, incorporating diet, weight and exercise history; confirmatory tests included pituitary MRIs, progestin challenges and endometrial thickness measurements. PCOS features of oligo/anovulation, polycystic ovarian morphology (PCOm) and hyperandrogenism were determined by clinical history, pelvic ultrasound, free androgen index and physical examination, respectively. Features of PCOS and blood levels of AMH, follicle‐stimulating hormone, luteinising hormone, sex hormone binding globulin (SHBG) and testosterone were compared between subgroups.

Results

Of 141 patients with elevated AMH, 76 were obese and 65 lean. Greater than one‐third of lean women had the clinical picture of FHH. Elevated AMH predicted PCOm and menstrual irregularity across all subgroups but uniquely associated with hyperandrogenism in the obese. Median AMH levels were similar among FHH and non‐FHH women. Median SHBG levels were significantly higher (111 ± 73 vs 56 ± 31, P < 0.001) in lean women with FHH compared to those without FHH.

Conclusions

PCOS and FHH share common features of elevated AMH levels, oligo‐anovulation and polycystic ovarian morphology. AMH did not assist in differentiating FHH from PCOS. A higher SHBG level shows promise as a discriminatory finding in FHH.
Beyond epithelial‐to‐mesenchymal transition: Common suppression of differentiation programs underlies epithelial barrier dysfunction in mild, moderate, and severe asthma
Authors: Loffredo L. F. , Abdala‐Valencia H. , Anekalla K. R. , Cuervo‐Pardo L. , Gottardi C. J. , Berdnikovs S.
Published: June 2017

Background

Epithelial barrier dysfunction is a central feature in the pathogenesis of allergic disease. Epithelial‐to‐mesenchymal transition (EMT) has been proposed as one mechanism afflicting barrier in asthma. However, genes and pathways involved in aberrant epithelial‐mesenchymal signaling, and their relationship to asthma severity, are poorly understood.

Methods

We used unbiased gene network analysis to evaluate functional convergence in epithelial gene expression signatures across multiple public access transcriptomics datasets of human asthma, followed by text mining to evaluate functional marker relevance of discovered genes. We objectively confirmed these findings in epithelial brushings and primary asthmatic epithelial cells cultured in different biological contexts.

Results

We found a striking suppression of epithelial differentiation in asthma, overrepresented by insufficiency in insulin and Notch signaling, but with the absence of conventional EMT markers. We identified EFNB2, FGFR1, FGFR2, INSR, IRS2, NOTCH2, TLE1, and NTRK2 as novel markers central to dysregulation of epithelial‐mesenchymal signaling, but surprisingly overlooked in asthma research. We found that this “core” signature of asthma is shared by mild, moderate, and severe forms of disease, progressing with severity. Loss of epithelial differentiation induced by insulin deprivation in normal human bronchial epithelial cells cultured in organotypic conditions closely approximated gene expression in asthmatic epithelial brushings.

Conclusions

The comparative analysis of publically available transcriptomes demonstrated that epithelial barrier dysfunction in asthma is characterized by persistent underlying de‐differentiation program with complex etiology. The lasting alteration of the asthmatic epithelial cell transcriptome implicates regulation involving metabolism and epigenetics, beyond EMT driven by injury and repair in chronic inflammation.
Cross‐border patient movement from the Lao PDR and the interplay between social networks and economic and cultural capital: A qualitative study
Authors: Durham Jo
Published: June 2017

Healthcare is most often examined within the confines of nation‐states. Such an analysis, however, is not necessarily indicative of reality, with people often travelling across borders for healthcare. This paper explores cross‐border travel for medical care by patients in the Lao People's Democratic Republic. The paper shows that while travelling across borders for medical care is not new, how, why and who travels across borders have changed in tandem with changes in the political and socio‐economic landscape. The paper is based on a review of the literature and qualitative interviews with patients who had crossed the border for planned healthcare (N = 43), Laotian medical officials working in public institutions (N = 5) and international health advisors (N = 6). Patients came from different districts, a range of socio‐economic backgrounds, had crossed borders for planned healthcare in the last two years and, based on key informant subjective assessments, were information‐rich respondents. The study reveals how Lao cross‐border patients creatively use the cultural and social resources at their disposal to obtain the healthcare they desire. In particular, it draws attention to the interplay between social, economic and cultural capital, and habitus in navigating access to transnational healthcare.
Laparoscopic segmental duodenectomy for a gastrointestinal stromal tumor located in the second portion of the duodenum: A case report
Authors: Umemoto Kazufumi , Nakanishi Yoshitsugu , Murakawa Katsuhiko , Suzuki Tomohiro , Yamamura Yoshiyuki , Ono Koichi , Hirano Satoshi
Published: June 2017

Gastrointestinal stromal tumors of the duodenum are rare. For benign tumors, premalignant lesions, or malignant potential tumors located in the second portion of the duodenum close to the papilla of Vater, pancreaticoduodenectomy is sometimes performed. A case of laparoscopic segmental duodenectomy for a gastrointestinal stromal tumor at the second portion of the duodenum is reported. The surgical procedure was performed as follows: first, the second portion of the duodenum was separated from the pancreatic head; second, the duodenum was cut off with the linear stapler after having confirmed preservation of the papilla by intraoperative endoscopy; and third, reconstruction was carried out by a side‐to‐side duodenojejunostomy. Laparoscopic segmental duodenectomy for duodenal gastrointestinal stromal tumors is thought to be advantageous compared with pancreaticoduodenectomy in terms of low burden and organ function preservation. The present procedure is feasible for benign or low‐malignant tumors that do not infiltrate outside of the duodenal walls.
The efficacy and safety of gemcitabine, cisplatin, prednisone, thalidomide versus CHOP in patients with newly diagnosed peripheral T‐cell lymphoma with analysis of biomarkers
Authors: Li Ling , Duan Wenjing , Zhang Lei , Li Xin , Fu Xiaorui , Wang Xinhua , Wu Jingjing , Sun Zhenchang , Zhang Xudong , Chang Yu , Nan Feifei , Yan Jiaqin , Li Zhaoming , Young Ken H. , Zhang Mingzhi
Published: June 2017

We compared the efficacy and safety of gemcitabine, cisplatin, prednisone and thalidomide (GDPT) with standard CHOP regimen (cyclophosphamide, doxorubicin, vincristine, prednisone) for patients with newly diagnosed peripheral T‐cell lymphoma (PTCL) in a prospective randomized controlled and open‐label clinical trial. Between July 2010 and June 2016, 103 patients were randomly allocated into two groups, of whom 52 were treated with GDPT therapy and 51 with CHOP therapy. The 2‐year progression‐free survival (PFS) and overall survival (OS) rates were better in the GDPT group than in the CHOP group (57% vs. 35% for 2‐year PFS, P = 0·0035; 71% vs 50% for 2‐year OS, P = 0·0001). The complete remission rate (CRR) and the overall response rate (ORR) in the GDPT group were higher than in the CHOP group (52% vs. 33%, P = 0·044 for CRR; 67% vs. 49%, P = 0·046 for ORR). Haemocytopenia was the predominant adverse effect, and acute toxicity was moderate, tolerable and well managed in both arms. mRNA expression of ERCC1, RRM1, TUBB3 and TOP2A genes varied among patients but the difference did not reach statistical significance, mainly due to the relatively small sample size. The precise characters of these biomarkers remain to be identified. In conclusion, GDPT is a promising new regimen as potential first‐line therapy against PTCL. This study was registered at www.clinicaltrials.gov as #NCT01664975.
Trafficking and localisation to the plasma membrane of Nav1.5 promoted by the β2 subunit is defective due to a β2 mutation associated with Brugada syndrome
Authors: Dulsat Gemma , Palomeras Sonia , Cortada Eric , Riuró Helena , Brugada Ramon , Vergés Marcel
Published: June 2017

Background Information

Cardiac channelopathies arise by mutations in genes encoding ion channel subunits. One example is Brugada Syndrome (BrS), which causes arrhythmias and sudden death. BrS is often associated with mutations in SCN5A, encoding Nav1.5, the α subunit of the major cardiac voltage‐gated sodium channel. This channel forms a protein complex including one or two associated β subunits as well as other proteins.

Results

We analysed regulation of Nav1.5 localisation and trafficking by β2, specifically, Nav1.5 arrival to the cell surface. We used polarised Madin‐Darby canine kidney (MDCK) cells and mouse atria‐derived HL‐1 cells, which retain phenotypic features of adult cardiomyocytes. In both, Nav1.5 was found essentially intracellular, mainly in the endoplasmic reticulum, whereas β2 localised to the plasma membrane, and was restricted to the apical surface in MDCK cells. A fraction of β2 interacted with Nav1.5, despite their limited overlap. Importantly, β2 promoted Nav1.5 localisation to the cell surface. Both β2 WT and the BrS‐associated mutation D211G (substitution of Asp for Gly) effectively reached the plasma membrane. Strikingly, however, β2 D211G was defective in promoting Nav1.5 surface localisation.

Conclusions

Our data sustain that β2 promotes surface localisation of Nav1.5, which can be affected due to β2 mutations associated with channelopathies.

Significance

Our findings add to the understanding of β2 role in Nav1.5 trafficking and localisation, which must influence cell excitability and electrical coupling in the heart. This study will contribute to knowledge on development of arrhythmias.
Introduction to the Special Section of Child Development on Positive Youth Development in Diverse and Global Contexts
Authors: Leman Patrick J. , Smith Emilie P. , Petersen Anne C. ,   SRCD Ethnic–Racial Issues and International Committees
Published: June 2017

Positive youth development (PYD) research seeks to understand and promote positive aspects of development in young people. In this the special section, focused upon youth from diverse racial–ethnic backgrounds around the globe, we describe the origins and development of the field, identify key and emerging themes, and present the challenges for work in the area in the years ahead. Central to these are elements that are inherent in many of the articles that constitute the section: These include a need to articulate more clearly the role of social and cultural context in positive development, a need to refine the measures and methods used for collecting data, the significance of social identities, and engagement with other fields of study and with policymakers.
Genetic polymorphisms and folate status
Authors: Hiraoka Mami , Kagawa Yasuo
Published: June 2017

Moderate hyperhomocysteinemia‐induced low folate status is an independent risk factor for cardiovascular disease, dementia, and depression. Folate is an essential cofactor in the one‐carbon metabolism pathway and is necessary in amino acid metabolism, purine and thymidylate synthesis, and DNA methylation. In the folate cycle and homocysteine metabolism, folate, vitamin B12, vitamin B6, and vitamin B2 are important cofactors. Many enzymes are involved in folate transport and uptake, the folate pathway, and homocysteine (Hcy) metabolism, and various polymorphisms have been documented in these enzymes. Serum folate and total Hcy (tHcy) levels are influenced by folate intake and genetic polymorphisms in 5,10‐methylenetertahydrofolate reductase (MTHFR) such as C677T. The prevalence of the MTHFR 677TT genotype varies across ethnic groups and regions, with a frequency of approximately 15% in Japanese populations. Individuals with the TT genotype have significantly higher tHcy levels and lower folate levels in serum than those with the CT and TT genotypes. However, administration of folic acid has been shown to eliminate these differences. Moreover, data have suggested that interventions based on genotype may be effective for motivating individuals to change their lifestyle and improve their nutrition status. Accordingly, in this review, we discuss the effects of MTHFR C677T polymorphisms on serum tHcy and folate levels with folic acid intervention and evaluate approaches for overcoming folic acid deficiency and related symptoms.