bluuebunny/crossref_metadata_2025 huggingface dataset:
A linearity-preserving vertex interpolation algorithm for cell-centered finite volume approximations of anisotropic diffusion problems
Authors: Yang Di , Gao Zhiming
Published: September 2019

Purpose

A finite volume scheme for diffusion equations on non-rectangular meshes is proposed in [Deyuan Li, Hongshou Shui, Minjun Tang, J. Numer. Meth. Comput. Appl., 1(4)(1980)217–224 (in Chinese)], which is the so-called nine point scheme on structured quadrilateral meshes. The scheme has both cell-centered unknowns and vertex unknowns which are usually expressed as a linear weighted interpolation of the cell-centered unknowns. The critical factor to obtain the optimal accuracy for the scheme is the reconstruction of vertex unknowns. However, when the mesh deformation is severe or the diffusion tensor is discontinuous, the accuracy of the scheme is not satisfactory, and the author hope to improve this scheme.

Design/methodology/approach

The authors propose an explicit weighted vertex interpolation algorithm which allows arbitrary diffusion tensors and does not depend on the location of discontinuity. Both the derivation of the scheme and that of vertex reconstruction algorithm satisfy the linearity preserving criterion which requires that a discretization scheme should be exact on linear solutions. The vertex interpolation algorithm can be easily extended to 3 D case.

Findings

Numerical results show that it maintain optimal convergence rates for the solution and flux on 2 D and 3 D meshes in case that the diffusion tensor is taken to be anisotropic, at times heterogeneous, and/or discontinuous.

Originality/value

This paper proposes a linearity preserving and explicit weighted vertex interpolation algorithm for cell-centered finite volume approximations of diffusion equations on general grids. The proposed finite volume scheme with the new interpolation algorithm allows arbitrary continuous or discontinuous diffusion tensors; the final scheme is applicable to arbitrary polygonal grids, which may have concave cells or degenerate ones with hanging nodes. The final scheme has second-order convergence rate for the approximate solution and higher than first-order accuracy for the flux on 2 D and 3 D meshes. The explicit weighted interpolation algorithm is easy to implement in three dimensions in case that the diffusion tensor is continuous or discontinuous.
Temperature identification of a heat source in conjugate heat transfer problems via an inverse analysis
Authors: Mayeli Peyman , Nikfar Mehdi
Published: September 2019

Purpose

The present study aims to perform inverse analysis of a conjugate heat transfer problem including conduction and forced convection via the quasi-Newton method. The inverse analysis is defined for a heat source that is surrounded by a solid medium which is exposed to a free stream in external flow.

Design/methodology/approach

The objective of the inverse design problem is finding temperature distribution of the heat source as thermal boundary condition to establish a prescribed temperature along the interface of solid body and fluid. This problem is a simplified version of thermal-based ice protection systems in which the formation of ice is avoided by maintaining the interface of fluid and solid at a specified temperature.

Findings

The effects of the different pertinent parameters such as Reynolds number, interface temperature and thermal conductivity ratio of fluid and solid mediums are analyzed.

Originality/value

This paper fulfils the analysis to study how thermal based anti-icing system can be used with different heat source shapes.
Flow and heat transfer past a permeable stretching/shrinking sheet in Cu−Al2O3/water hybrid nanofluid
Authors: Yahaya Rusya Iryanti , Arifin Norihan M. , Nazar Roslinda , Pop Ioan
Published: September 2019

Purpose

The purpose of this paper is to study the flow and heat transfer of a hybrid nanofluid, Cu–Al2O3/water, past a permeable stretching/shrinking sheet. The effects of Brownian motion and thermophoresis are considered here.

Design/methodology/approach

Similarity transformations are used to reduce the governing partial differential equations to a system of ordinary (similarity) differential equations. A MATLAB solver called the bvp4c is then used to compute the numerical solutions of equations (12) to (14) subject to the boundary conditions of equation (15). Then, the effects of various physical parameters on the flow and thermal fields of the hybrid nanofluid are analyzed.

Findings

Multiple (dual) solutions are found for the basic boundary layer equations. A stability analysis is performed to see which solutions are stable and, therefore, applicable in practice and which are not stable. Besides that, a comparison is made between the hybrid nanofluid and a traditional nanofluid, Cu/water. The skin friction coefficient and Nusselt number of the hybrid nanofluid are found to be greater than that of the other nanofluid. Thus, the hybrid nanofluid has a higher heat transfer rate than the other nanofluid. However, the increase in the shrinking parameter reduces the velocity of the hybrid nanofluid.

Originality/value

The present results are original and new for the study of the flow and heat transfer past a permeable stretching/shrinking sheet in Cu–Al2O3/water hybrid nanofluid.
Numerical simulation of the fractional Lienard’s equation
Authors: Alchikh Razan , Khuri Suheil
Published: September 2019

Purpose

The purpose of this paper is to apply an efficient semi-analytical method for the approximate solution of Lienard’s equation of fractional order.

Design/methodology/approach

A Laplace decomposition method (LDM) is implemented for the nonlinear fractional Lienard’s equation that is complemented with initial conditions. The nonlinear term is decomposed and then a recursive algorithm is constructed for the determination of the proposed infinite series solution.

Findings

A number of examples are tested to explicate the efficiency of the proposed technique. The results confirm that this approach is convergent and highly accurate by using only few iterations of the proposed scheme.

Originality/value

The approach is original and is of value because it is the first time that this approach is used successfully to tackle fractional differential equations, which are of great interest for authors in the recent years.
Lagrange crisis and generalized variational principle for 3D unsteady flow
Authors: He Ji-Huan
Published: September 2019

Purpose

A three-dimensional (3D) unsteady potential flow might admit a variational principle. The purpose of this paper is to adopt a semi-inverse method to search for the variational formulation from the governing equations.

Design/methodology/approach

A suitable trial functional with a possible unknown function is constructed, and the identification of the unknown function is given in detail. The Lagrange multiplier method is used to establish a generalized variational principle, but in vain.

Findings

Some new variational principles are obtained, and the semi-inverse method can easily overcome the Lagrange crisis.

Practical implications

The semi-inverse method sheds a promising light on variational theory, and it can replace the Lagrange multiplier method for the establishment of a generalized variational principle. It can be used for the establishment of a variational principle for fractal and fractional calculus.

Originality/value

This paper establishes some new variational principles for the 3D unsteady flow and suggests an effective method to eliminate the Lagrange crisis.
High-temperature tribological behavior of Mo and BaF2 added Cr3C2-NiCr matrix composite
Authors: Zhao Hailong , Luo Lirong , Guo Fangwei , Zhao Xiaofeng , Xiao Ping
Published: September 2019

Purpose

The purpose of this paper is to investigate the tribological performance of Cr3C2–NiCr–Mo–BaF2 composite sliding against a Si3N4 ball at high temperatures.

Design/methodology/approach

A Cr3C2–NiCr composite and a Cr3C2–NiCr–Mo–BaF2 composite were prepared using spark plasma sintering. Tribological properties of the composites were investigated using a ball-on-disk type tribotester. The relationships among the microstructure, wear mechanism and tribological performance were determined by analyzing the wear track morphologies and the glaze layer’s phase composition.

Findings

The wear rate of the Cr3C2–NiCr–Mo–BaF2 composite was approximately one order of magnitude lower than that of the Cr3C2–NiCr composite from 700°C to 900°C when sliding against a Si3N4 ball. The favorable tribological performance of the Cr3C2–NiCr–Mo–BaF2 composite at high temperatures results from the synergistic lubrication of MoOx, BaF2 and BaMoO4.

Originality/value

This paper reports a new Cr3C2–NiCr matrix self-lubricating composite with better tribological properties than Cr3C2–NiCr composite at temperatures up to 900°C through Mo and BaF2 addition.
Stiffness model of fixed joint considering self-affinity and elastoplasticity of asperities
Authors: Chen Hongxu , Yin Qin , Dong Guanhua , Xie Luofeng , Yin Guofu
Published: September 2019

Purpose

The purpose of this paper is to establish a stiffness model of fixed joint considering self-affinity and elastoplasticity of asperities.

Design/methodology/approach

The proposed model considers that asperities of different scales are interrelated rather than independent. For elastoplastic contact, a spring-damper model and an elastic deformation ratio function were proposed to calculate the contact stiffness of asperities.

Findings

A revised fractal asperity model was proposed to calculate the contact stiffness of fixed joint, the impacts of the fractal dimension, the fractal roughness parameter and the Meyer index on the contact stiffness were discussed, and the present experimental results and the Jiang’s experimental results showed that the stiffness can be well predicted by proposed model.

Originality/value

The contradiction between the Majumdar and Bhushan model and the Morag and Etsion model can be well explained by considering the interaction among asperities of different scales. For elastoplastic contact, elastic deformation ratio should be considered, and the stiffness of asperities increases first and then decreases with the increasing of interference.
The effect of lubricant viscosity model with improver on friction and lubrication of piston skirt-cylinder liner conjunction
Authors: Xin Gu , Liu Xiao-Ri , Cheng Dong-Kang , Zheng Qing-Ping , Li Meng-Han , Sun Nan-Nan , Min Chun-Hua
Published: September 2019

Purpose

This paper aims to investigate the effect of lubricant viscosity model with improver on friction and lubrication of piston skirt-cylinder liner conjunction.

Design/methodology/approach

A dynamic calculation model is established for the piston skirt-cylinder liner conjunction of a heavy-duty commercial diesel engine, to explore the effects of two kinds of lube oil viscosity models named after polyalkyle-metacrylate-1 (PAMA1) and styrene-isoprene-copolymer (SICP) improvers on the maximum oil film viscosity, the minimum oil film thickness, the peak oil film pressure, the maximum shear rate, the friction force and the total friction power loss.

Findings

The variation trends with the crank angle of the above parameters are not changed with the difference of improvers, while obvious numerical differences are found except the maximum oil film pressure. The minimum oil film thickness and maximum shear rate of PAMA1 are larger than that of SICP, the maximum oil film viscosity of SICP is larger than that of PAMA1, which indicates that the shear-thinning effect of PAMA1 is greater, the maximum friction force on the piston of SICP is larger than that of PAMA1, and the total friction power consumption is also larger, the average friction power consumptions of SICP and PAMA1 are 385.4 and 262.8 W, respectively, with the relative difference of 31.8 per cent.

Originality/value

The influence of different lubricating oil additive models on the lubrication and friction of piston skirt-cylinder liner conjunction is simulated and analyzed.
Influence of structural parameters of friction pair on oil temperature rise in hydro-viscous clutch
Authors: Li Zhibao , Xie Fangwei , Sun Junyu , Zhu Jie , Zheng Xudong , Guo Xinjian , Wang Yun , Hua Yinqun
Published: September 2019

Purpose

The purpose of this paper is to study the temperature characteristics of hydro-viscous clutch with different structure of friction disks and obtain the distribution of film temperature.

Design/methodology/approach

The mathematical model of oil film between friction disks with radial grooves is established. Based on the flow rate equation, the temperature rise equation of oil film is deduced. Considering two-phase flow, the temperature distribution in the oil shear stage and the effects of the ratio of inner radius to outer radius on film temperature rise is studied by using computational fluid dynamics (CFD) technology.

Findings

The results show that when input speed is constant, the increase in the ratio of inner to outer radius leads to an increase in the peak temperature and the decrease in the ratio results in a larger increasing rate of temperature.

Originality/value

These results are of interest for the study of hydro-viscous drive and its applications. This study can also provide a theoretical basis for the mechanism of temperature rise by considering the effect of two-phase flow.
Experimental and numerical investigation of the effect of pre-existing utility tunnel on the bearing capacity of shallow footing in sandy soils
Authors: Malhotra Monica , Sahu Vaishali , Srivastava Amit , Misra Anil Kumar
Published: September 2019

Purpose

The purpose of this study is to investigate the effect of presence of buried flexible pipe on the bearing capacity of shallow footing. First, a model study is performed where shallow footing model is tested for its load settlement behavior, with and without the existence of buried PVC pipe lying vertically below the base of the footing.

Design/methodology/approach

The experimental set-up consisted of a steel box filled with sand at two different relative density values [RD = 50 per cent (medium dense) and RD = 80 per cent (dense sand)] and vertical load was applied on the model footing through hydraulic jack and reaction frame arrangement connected with a proving ring. Test results are verified numerically using commercially available finite element code PLAXIS 2D. With due verification, a parametric study has been conducted, numerically, by varying the range of input parameters, such as unit weight, angle of internal friction, diameter of buried conduit and the Elastic modulus of the soil to assess the pre cent reduction in the capacity of the foundation soil because of the presence of underlying buried flexible pipe.

Findings

Results show that for each footing, there exists a critical depth below which the presence of the buried conduit has negligible influence on the footing performance. When the conduit is located above the critical depth, the bearing capacity of the footing varies with various factors, such as geotechnical parameters of soil and location and diameter of the buried conduit.

Originality/value

It is an original paper performed to assess the presence of buried flexible pipe on the bearing capacity of the shallow footing.
Fuzzy-analytical-hierarchy process in failure mode and effect analysis (FMEA) to identify process failure in the warehouse of a cement industry
Authors: Hassan Azmi , Purnomo Muhammad Ridwan Andi , Anugerah Adhe Rizky
Published: September 2019

Purpose

This paper aims to identify and reduce possible process failures occurred in warehouse.

Design/methodology/approach

This research used risk analysis method FMEA combined with fuzzy-analytical hierarchy process (AHP). Design FMEA will direct the failure mode or failure of components into levels and will use it to analyze the product before it used in manufacturing processes. Design FMEA has a major point on the failure mode that caused inefficiency in the design while fuzzy-AHP used to reduce subjectivity in the weighting process.

Findings

The results show that high inventory is the dominant factor that must be controlled by the company to prevent the risk of failure processes in the warehouse, followed by the number of stocks that do not match with existing records, and misplacement of machines and/or materials.

Originality/value

This research used risk analysis method FMEA combined with fuzzy-AHP to identify and reduce the possible process failures in warehousing.
Comparing STATIC-99R and STABLE-2007 between persons with and without intellectual disabilities
Authors: Delforterie Monique , van den Berg Jan Willem , Bolt Betto , van den Hazel Teunis , Craig Leam , Didden Robert
Published: September 2019

Purpose

While there is a significant proportion of people with a mild intellectual disability (MID) or borderline intellectual functioning (BIF) who commit sexual offenses, little research has focused on the risk factors for sexual recidivism in people with MID-BIF. The purpose of this paper is to compare the scores on the STATIC-99R and STABLE-2007 between persons with sexual offense histories with and without MID-BIF.

Design/methodology/approach

Data using the STATIC-99R and STABLE-2007 were collected in 85 male patients divided into an MID-BIF group (IQ 50–85,n=50) and comparison group (IQ>95,n=35).

Findings

The MID-BIF group and comparison group did not differ significantly on the static risk factors and total score of the STATIC-99R. However, of the 13 dynamic risk factors of the STABLE-2007, the MID-BIF group scored significantly higher on the items Impulsive acts, Poor problem solving skills and Lack of concern for others, while the comparison group scored significantly higher on the item Deviant sexual preference.

Originality/value

The higher score on a number of dynamic risk factors for patients with MID-BIF could partly be explained by the characteristics associated with MID-BIF. Although dynamic criminogenic risk factors which are usually identified as targets for treatment appear the same for people with and without MID-BIF who commit sexual offenses, adaptations to the modality of treatment will still need to be made for people with MID-BIF.
An optimal charging strategy for crowdsourcing platforms
Authors: Chen Jiumei , Liu Zhiying , Zhang Wen , Gong Bengang
Published: September 2019

Purpose

The purpose of this paper is to develop an optimal charging strategy for a third-party crowdsourcing platform.

Design/methodology/approach

Based on the auction theory, the Stackelberg game theory and the systems theory, this paper presents a new model from the perspective of risk sharing between solution seekers and the crowdsourcing platform, given the utility maximization of the seekers, the crowdsourcing platform and the solvers.

Findings

Based on the results, this study shows that the menu of fees, which includes different combinations of a fixed fee and a floating fee schedule, should be designed to attract both solution seekers and solvers. In addition, the related prize setting and the expected payoff for each party are presented.

Practical implications

This study is beneficial for crowdsourcing platform operators, as it provides a new way to design charging strategies and can help in understanding key influential factors.

Originality/value

To the best of the authors’ knowledge, this study is one of the first to simulate the interactions among the three stakeholders, thereby providing a novel model that includes a fixed fee and a floating commission.
Pathogenic role of palatine tonsils in palmoplantar pustulosis: A review
Authors: Harabuchi Yasuaki , Takahara Miki
Published: September 2019

Palmoplantar pustulosis (PPP) is characterized by symmetrical, erythematous, scaly plaques, with numerous, sterile, non‐bacterial, pinpoint pustules, which are restricted to the palms and soles. Because several reports have described the efficacy of tonsillectomy for improvement in PPP skin lesions, we consider that PPP is tonsil‐induced autoimmune/inflammatory syndrome (TIAS) while other factors are also involved in the pathogenesis of PPP. Here, the association between PPP pathogenesis and TIAS was examined, with a focus on results of previous studies. PPP patients show a hyperimmune response to indigenous bacteria such as α‐streptococci, due to impaired immunological tolerance towards such organisms. Such a novel immune response leads to T‐cell activation through the abnormal expression of secondary stimulation molecules, including cytotoxic T‐lymphocyte‐associated antigen 4, inducible T‐cell co‐stimulator and Smad7, in the tonsils of PPP patients. Activated tonsillar T cells express cutaneous lymphocyte antigen (CLA), CCR6 and β1‐integrin, enter the blood circulation and are recruited to PPP skin lesions. Within lesions, T cells roll onto endothelial cells through the interaction between CLA and E‐selectin, migrate into the extravascular area through β1‐integrin–vascular cell adhesion molecule 1 binding, and assemble in the skin through CCL20–CCR6 binding. Hyperimmune responses to autoantigens such as keratin and heat shock proteins could also be involved in PPP pathogenesis, through the stimulation of the T‐helper 17 reaction.
Legal Systems, National Governance and Renewable Energy Investment: Evidence from Around the World
Authors: Liu Jia , Zhang Dayong , Cai Jing , Davenport John
Published: September 2019

This paper examines renewable energy (RE) investment and the role of a country's legal system in shaping investment decisions. Analysing data from 236 renewable energy companies between 2000 and 2017 across the world, our study establishes that those in a common law system are more responsive to growth opportunities in RE investment, while facing greater financial constraints than their counterparts in civil law systems. Our study demonstrates that the global imbalance in RE development is caused by the influence of a country's legal system, which determines the regulatory and business ethos that impacts on the trajectory of investment, and by the varying degrees of accountability implicit in a country's governance environment. Our research raises the implication that the opportunity costs of forgone economic gains are in direct conflict with long‐term environmental goals, retarding the transition from carbon‐based to sustainable sources of energy, and provides insights into how development can be stimulated by fiscal incentives, favourable regulations, societal engagement, improved access to finance and the alignment of national strategies. Our findings contribute to the economic literature of legal origin theory and establish fundamental principles for refining global RE development strategy and confronting the challenge of climate change.
Corporations as Moral Agents: Trade‐Offs in Criminal Liability and Human Rights for Corporations
Authors: Friedman Nick
Published: September 2019

This article argues that a common way of defending corporate criminal liability creates a dilemma: it provides a strong justification for giving human rights to corporations. This result follows from approaches to punishment and human rights which predicate each on the status of moral agency. In short, if corporations are moral agents in a sufficient sense to attract criminal liability, they are eligible holders of human rights. The article also discusses the doctrinal application of this philosophical claim. Drawing on US jurisprudence, it illustrates how the European Court of Human Rights might deploy corporate moral agency as a theoretical foundation for its otherwise weakly‐reasoned attribution of human rights to corporations. If proponents of corporate criminal liability are dissatisfied with these conclusions, they face difficult policy trade‐offs: they must abandon the doctrine, or adopt alternative approaches to punishment or human rights.
Intranasal nanoemulsion vaccine confers long‐lasting immunomodulation and sustained unresponsiveness in a murine model of milk allergy
Authors: O'Konek Jessica J. , Landers Jeffrey J. , Janczak Katarzyna W. , Lindsey Hayley K. , Mondrusov Anna M. , Totten Tiffanie D. , Baker James R.
Published: September 2019

Background

Immunotherapy for food allergy requires prolonged treatment protocols and, in most cases, does not lead to durable modulation of the allergic immune response. We have demonstrated an intranasal (IN) nanoemulsion adjuvant that redirects allergen‐specific Th2 responses toward Th1 and Th17 immunity, and protects from allergen challenge after only 2‐4 monthly administrations. Here, we investigate the ability of this technology to provide long‐term modulation of allergy in a murine model of cow's milk allergy.

Methods

Six weeks after sensitization to bovine casein, mice received four, monthly IN immunizations with nanoemulsion formulated with casein. Protection from casein challenge was assessed at 4 and 16 weeks after the final vaccine administration.

Results

The NE vaccine significantly blunted the physiological responses to allergen challenge, and this effect persisted for at least 16 weeks. The protection from challenge was associated with the suppression of casein‐specific Th2 immunity and induced Th1 and Th17 cytokines as well as induction of IL‐10. Of interest, while immunized animals showed significantly decreased Th2 cytokine responses, cow's milk‐specific IgE remained elevated in the serum at levels associated with reactivity in control sensitized animals. Protection was associated with suppressed mast cell activation and markedly reduced mast cell infiltration into the small intestine.

Conclusion

The sustained unresponsiveness of at least 16 weeks after vaccination suggests that the nanoemulsion vaccine alters the allergic phenotype in a persistent manner different from traditional desensitization, and this leads to long‐term suppressive effects on allergic disease without eliminating serum IgE.
Changing QRS duration and morphology with A‐paced and A‐sensed rhythm in postcardiac resynchronization therapy (CRT) patients
Authors: Deshpande Saurabh Ajit , Udyavar Ameya
Published: September 2019

Meticulous interpretation of the ECGs of patients with cardiac resynchronization defibrillator therapy (CRT‐D) device is important to ensure optimal synchronization of both the chambers. We present the ECGs of such a patient who was noted to have different morphologies of the biventricular‐paced QRS depending in atrial‐sensed (A‐sensed) or atrial‐paced (A‐paced) rhythm.
FISCAL DECENTRALIZATION AND ECONOMIC GROWTH OF VIETNAMESE PROVINCES: THE ROLE OF LOCAL PUBLIC GOVERNANCE
Authors: THANH Su Dinh , CANH Nguyen Phuc
Published: September 2019

This study offers an insight into the public governance role in the relationship between fiscal decentralization and provincial economic growth in Vietnam. Fiscal decentralization measures are assorted. Applying a sequential (two‐stage) estimation for the panel data of 62 provinces of Vietnam over the 2006–2015 period, we find that first, fiscal decentralization is positively related to the economic growth of Vietnamese provinces. Second, the effects of public governance on economic growth vary across provinces depending on various levels of local public governance. Interestingly, the effect of fiscal decentralization is strengthened when this variable is added along with better quality of public governance. In a region of high public governance quality, fiscal decentralization exerts a positive effect on its economic growth. Our findings imply that the design of fiscal decentralization needs to be associated with local governments’ ability of public governance to improve the local economic growth.
Preschoolers’ sharing expectations towards friends relate to their kindergarten peer status
Authors: Essler Samuel , Wörle Monika , Moore Chris , Paulus Markus
Published: September 2019

Recent research has provided evidence for a substantial impact of children's peer status on positive and adaptive development. The current study investigated how 3‐ to 7‐year‐old preschoolers’ (N = 118) sharing behaviour and sharing expectations towards a friend and a non‐friend relate to their popularity among their peers. Children distributed resources between themselves and a friend as well as themselves and a non‐friend and predicted another protagonist's behaviour in the same situation. In addition, teachers rated children's problematic behaviour and peers rated children's peer status. Multilevel analysis revealed that preschoolers’ sharing expectations towards their friends but not sharing behaviour predicted their peer status above and beyond the impact of problematic behaviour. Age did not emerge as an independent predictor. These findings suggest that knowledge about prosociality in the form of sharing expectations is an important aspect in children's adaptive social development and stress the relevance of children's knowledge about the social world for their social life.

Statement of contribution

What is already known on this subject?

Prosocial behaviour in general relates positively to peer status.

Problem behaviour relates negatively to peer status.

Sharing behaviour and sharing expectations become more selective over the preschool years.

What does this study add?

Sharing expectations and to a lesser extent sharing behaviour relate to peer status.

Sharing expectations predict peer status above and beyond the impact of problem behaviour.

Differential sharing expectations predict peer status as well as simple sharing expectations.
Circulating gut microbiota metabolite trimethylamine N‐oxide and oral contraceptive use in polycystic ovary syndrome
Authors: Eyupoglu Nesrin Damla , Caliskan Guzelce Ezgi , Acikgoz Aylin , Uyanik Esra , Bjørndal Bodil , Berge Rolf K. , Svardal Asbjørn , Yildiz Bulent Okan
Published: September 2019

Objectives

Polycystic ovary syndrome (PCOS) is associated with an increased cardiometabolic risk that might not necessarily translate into adverse cardiovascular outcome later in life. Recently, alterations in gut microbial composition have been reported in the syndrome. Microbiota‐dependent metabolite trimethylamine N‐oxide (TMAO) and its precursors are closely linked with development of atherosclerotic cardiovascular disease, independently of traditional risk factors. We aimed to assess whether TMAO and its precursors are altered in PCOS and to determine potential impact of treatment on these metabolites.

Design

Prospective study.

Patients

Twenty‐seven overweight/obese patients with PCOS and 25 age‐ and BMI‐matched healthy control women.

Measurements

At baseline, fasting serum TMAO and its precursors were measured after a 3‐day standardized diet. Patients received 3‐month OC therapy along with general dietary advice after which all measurements were repeated.

Results

Patients had higher total testosterone (T) and free androgen index (FAI) whereas whole‐body fat mass, fasting plasma glucose, insulin and lipids were similar between the groups. PCOS group showed significantly higher serum levels of TMAO and its precursors; choline, betaine and carnitine. TMAO and choline showed correlations with T. After 3 months of OC use, TMAO and its precursors significantly decreased along with reductions in BMI, T and FAI.

Conclusions

This study reports for the first time that TMAO and its precursors are elevated in PCOS which might contribute to increased cardiometabolic risk of the syndrome and that short‐term OC use along with lifestyle intervention is associated with reduction of these microbiome‐dependent metabolites.
Blood pressure in pregnancy—A stress test for hypertension? Five‐year, prospective, follow‐up of the ROLO study
Authors: Brady Michelle B. , O’Brien Eileen C. , Geraghty Aisling A. , Courtney Amanda U. , Kilbane Mark T. , Twomey Patrick J. , McKenna Malachi J. , Crowley Rachel K. , McAuliffe Fionnuala M.
Published: September 2019

Objective

To investigate whether maternal blood pressure (BP) below the diagnostic criteria of hypertensive disorders of pregnancy (HDP) is associated with maternal BP 5 years later.

Design

Prospective, observational study.

Setting

Dublin, Ireland (2007‐2011).

Sample

Three hundred twenty‐nine women from the ROLO study (Randomized cOntrol trial of LOw glycaemic index diet to prevent the recurrence of macrosomia).

Methods

Maternal BP measurements were taken during pregnancy (13, 28 and 34 weeks’ gestation and day 1 postpartum) and at the 5‐year follow‐up. Systolic BP (SBP) and diastolic BP (DBP) were categorized as normal (SBP < 120 and DBP < 80 mm Hg), elevated (SBP 120‐129 and DBP < 80 mm Hg), HTN stage 1 (SBP 130‐139 or DBP 80‐89 mm Hg) or HTN stage 2 (SBP ≥ 140 or DBP ≥ 90 mm Hg) at each timepoint.

Main Outcome Measures

Maternal blood pressure at the 5‐year follow‐up.

Results

Women with elevated BP at 28 and 34 weeks’ gestation had 2.68 (95% CI: 1.36‐5.26) and 2.45‐fold (95% CI: 1.22‐4.95) increased odds of HTN stage 1 respectively, at the 5‐year follow‐up, compared to those with normal BP in pregnancy.

Conclusion

Elevated BP at 28 and 34 weeks’ gestation was associated with an increased risk of HTN stage 1 at 5 years later. Thus, raised BP, below the diagnostic criteria of HDP, could be flagged for follow‐up postpartum.
Witnessing four decades of change in coastal park management: Interview with Mike Dodkin
Authors: Dodkin Mike , McDonald Tein
Published: September 2019

Mike Dodkin’s career as an officer with the NSW National Park and Wildlife Service spanned four decades. His work involved ecological surveys of potential new conservation reserves, overseeing rehabilitation works after mineral sand mining, supporting innovative restoration projects in rainforest and coastal dunes, and pioneering work in marine mammal rescue. In this interview, Mike reflects on those activities and the changes he has witnessed over time.
Coparenting Conflict and Cooperation between Parents and Grandparents in Vietnamese Families: The Role of Grandparent Psychological Control and Parent–Grandparent Communication
Authors: Hoang Nam‐Phuong T. , Haslam Divna , Sanders Matthew
Published: September 2019

Shared care between parents and grandparents is common in Asian cultures. This cocare practice provides many benefits to families but is also particularly complex, as both parents and grandparents must simultaneously fulfill their roles as cocaregivers as well as maintain their relationship with each other. This study aims to explore the determinants of coparenting relationships between parents and grandparents in Vietnam. Data were collected from 501 Vietnamese parents whose aging parents are active carers for their children. The results indicated that grandparent psychological control and parent–grandparent quality of communication explain the largest variance in both parent–grandparent coparenting conflict and cooperation. The results suggest that parenting interventions aimed at the Asian cultures, where grandparent care is common, may benefit from the inclusion of a content focus on promoting the coparenting relationship between parents and grandparents.
In SituU‐Th‐Pb Dating and Sr‐Nd Isotope Analysis of Bastnäsite by LA‐(MC)‐ICP‐MS
Authors: Yang Yue‐Heng , Wu Fu‐Yuan , Li Qiu‐Li , Rojas‐Agramonte Yamirka , Yang Jin‐Hui , Li Yang , Ma Qian , Xie Lie‐Wen , Huang Chao , Fan Hong‐Rui , Zhao Zi‐Fu , Xu Cheng
Published: September 2019

Bastnäsite is the end member of a large group of carbonate–fluoride minerals with the common formula (REE) CO3F·CaCO3. This group is generally widespread and, despite never occurring in large quantities, represents the major economic light rare earth element (LREE) mineral in deposits related to carbonatite and alkaline intrusions. Since bastnäsite is easily altered and commonly contains inclusions of earlier‐crystallised minerals,in situanalysis is considered the most suitable method to measure its U‐Th‐Pb and Sr‐Nd isotopic compositions. Electron probe microanalysis and laser ablation (multi‐collector) inductively coupled plasma‐mass spectrometry of forty‐six bastnäsite samples from LREE deposits in China, Pakistan, Sweden, Mongolia, USA, Malawi and Madagascar indicate that this mineral typically has high Th and LREE and moderate U and Sr contents. Analysis of an in‐house bastnäsite reference material (K‐9) demonstrated that precise and accurate U‐Th‐Pb ages could be obtained after common Pb correction. Moreover, the Th‐Pb age with its high precision is preferable to the U‐Pb age because most bastnäsites have relatively high Th rather than U contents. These results will have significant implications for understanding the genesis of endogenous ore deposits and formation processes related to metallogenic geochronology research.
Effect of thermal pre‐treatment on the phenolic and protein profiles and oil oxidation dynamics of golden flaxseeds
Authors: Waszkowiak Katarzyna , Mikołajczak Beata , Gliszczyńska‐Świgło Anna , Niedźwiedzińska Karina
Published: September 2019

The food industry is interested in the application of thermally pre‐treated flaxseeds because the treatment improves their sensory acceptability and reduces anti‐nutrient contents. However, it may influence the health benefits of flaxseed compounds. The changes in the phenolic and protein profiles, and in situ oil oxidation dynamics after steaming or roasting of flaxseeds were analysed to study this effect. The results showed that the pre‐treatment of flaxseeds did not affect the content of major flaxseed phenolics. Steaming and roasting considerably changed the flaxseed protein profile. The thermally induced protein aggregation and/or cross‐linking occurred. The most significant changes were found for the 13 and 53 kDa proteins. Flaxseed roasting deteriorated the oil oxidative stability significantly more than steaming. These changes may decrease the nutritional quality and shelf life of roasted or steamed flaxseeds. They should be monitored when pre‐treated flaxseeds are intended to be used as a food ingredient.
Interaction of whey protein with polyphenols from salal fruits (Gaultheria shallon) and the effects on protein structure and hydrolysis pattern by Flavourzyme®
Authors: Ni He , Hayes Helen , Stead David , Liu Guang , Yang Huaijie , Li Haihang , Raikos Vassilios
Published: September 2019

Milk whey can interact with polyphenols leading to the formation of complexes. In this research, whey protein was fortified with salal fruits (SB) extract and the effect on protein structure was investigated. Particle size and tertiary structure analysis indicates α‐lactalbumin–ligand interactions when whey is supplemented with SB extract. Circular dichroism spectroscopy suggests conformational changes of α‐Lac to a partially unfolded state as indicated by the decrease in α‐helix structures. Enzymatic treatment of whey protein mixed with SB revealed differences in the hydrolysis pattern. LC‐MS/MS data analysis indicates that a higher number of peptides are released when whey is mixed with SB. Peptides of known bioactivity were identified in all hydrolysates. The supplementation of whey protein with SB extract can influence protein hydrolysis and the release of peptides following enzymatic treatment with commercial proteases which may affect the functional and health‐related properties of the hydrolysate.
Clonal redemption and clonal anergy as mechanisms to balance B cell tolerance and immunity
Authors: Burnett Deborah L. , Reed Joanne H. , Christ Daniel , Goodnow Christopher C.
Published: September 2019

The adaptive immune system is tasked with producing antibodies that recognize a wide scope of potential pathogens, including those never before encountered, and concurrently avoiding formation of antibodies binding host tissues. The diverse repertoire of antibodies produced by V(D)J recombination inevitably includes autoantibodies that bind to self‐antigens, estimated to be as much as 70% of nascent antibodies on immature B cells. Early theoretical models of tolerance hypothesized that such self‐reactive clones could not possibly be allowed to survive and mature. However from the first direct view of the fate of nascent B cells carrying a self‐binding antibody it was clear that many “forbidden clones” circulate to secondary lymphoid tissues, where they adopt an IgMlow IgD+ cell surface phenotype and are prevented from secreting autoantibodies by a series of tolerance checkpoints referred to as “clonal anergy.” Since anergic B cells can be reactivated to secrete pathogenic autoantibodies in certain settings, the advantage of controlling self‐reactive antibodies by clonal anergy has until recently remained enigmatic. Here we review this topic and recent advances showing that anergic B cells are recruited into the germinal center to mutate away from self‐reactivity, undergoing “clonal redemption” into cells making antibodies with exquisite specificity for foreign immunogens.
Epitaxial, electro‐optically active barium titanate thin films on silicon by chemical solution deposition
Authors: Edmondson Bryce I. , Kwon Sunah , Lam Chon H. , Ortmann J. Elliott , Demkov Alexander A. , Kim Moon J. , Ekerdt John G.
Published: September 2019

Recent progress in the integration of BaTiO3 thin films with silicon has shown great promise for the development of on‐chip photonic devices. However, the highest performing thin films in the literature are deposited by costly and/or complex vacuum techniques. In this study, epitaxial BaTiO3 thin films are deposited on thin SrTiO3 template layers on Si(001) from an alkoxide‐based chemical solution under atmospheric conditions and yield an effective Pockels coefficient of 27 ± 4 pm/V for an ~85 nm film. Film crystallinity, microstructure, and defect nature are examined by X‐ray diffraction and high‐resolution transmission and scanning electron microscopy techniques and discussed within the context of the growth method as well as the observed electro‐optical response.
Umbilical Cord Practices of Members of the American College of Nurse‐Midwives
Authors: Leslie Mayri Sagady , Erickson‐Owens Debra , Park Jeongyoung
Published: September 2019

Introduction

The purpose of this survey of American College of Nurse‐Midwives (ACNM) members was to describe umbilical cord practices of US midwives and to explore possible modifying factors. Contrasting this study with the 2000 survey of ACNM members on umbilical cord clamping by Mercer, Nelson, and Skovgaard, we hypothesized that there would be an increase in utilization of delayed cord clamping at birth by current midwives. The benefits of adequate placental transfusion at birth via delaying cord clamping (DCC) has been well described for both preterm and term neonates. Surveys and observations of provider practice across the globe show inconsistent uptake of the evidence‐based practices of DCC and cord milking. This study provides a 17‐year update to the Mercer et al study and gives the opportunity for current assessment of umbilical cord management by members of ACNM.

Methods

This was a cross‐sectional study of 1050 active members of ACNM who had attended women in labor and birth within 3 years of the survey. Participants were selected using non‐probability, purposive sampling with recruitment through serial e‐mails. Umbilical cord practices were assessed, and related factors were examined using Chi‐square tests and multivariate logistic regression models.

Results

The overall response rate was 20%. Ninety‐two percent of the midwives performed DCC in this study as compared with 67% in the initial survey done in 2000. Over 50% of the midwives considered DCC in the presence of the following situations: shoulder dystocia, meconium‐stained fluid, and vaginal birth for a non‐reassuring fetal heart rate tracing. Twenty‐six percent said they would delay clamping if resuscitation was required. “I don't know” was the most common response when it came to cord management for breech births or when vacuum or forceps were used. Cord milking was used less frequently than DCC.

Discussion

Midwifery use of DCC has expanded since 2000. The use of cord milking is variable with concerns about the validity of the practice. For many participants, uncertainty is present regarding cord clamping in complex clinical situations. The study provides important guidance for addressing knowledge deficits and continual improvement in practice.
The utility of plastron shape for uncovering cryptic diversity in Hermann's tortoise
Authors: Djurakic M. R. , Milankov V. R.
Published: September 2019

Although a significant unexploited potential of the geometric morphometrics in taxonomy and systematics has been documented, only a few studies so far have focused on the utility of this method in the detection of population genetic structure in turtles. For the first time, we employed geometric morphometrics to explicitly analyse whether populations possessing divergent haplotypes evolved different patterns of plastral shape in any Testudo species using the Greek populations of Hermann's tortoise as a case study. To molecularly characterize the Greek populations of Testudo hermanni boettgeri used for plastron shape analyses, 12s rRNA gene of tortoises sampled from seven localities in Greece was sequenced. Three divergent haplotypes were observed, regionally corresponding to the north‐western (HI), south‐western (HII) and Peloponnese (HIII) areas of Greece. In both females and males, haplotypes HI and HII showed the lack of plastral shape divergence, but were both statistically significantly different relative to HIII found in Peloponnese. The Peloponnesian populations (HIII) had longer bridges and the wider and shorter anterior part of the plastron, relative to populations from the mainland Greece (HI and HII). Hence, both morphological and molecular markers suggested Peloponnese as a distinct lineage in relation to mainland populations. Finally, we consider geometric morphometrics as an efficient method to detect and characterize subtle interpopulation differences. Findings in this study have conservation applications as well, implying the presence of cryptic genetic and taxonomic diversity, and, thus, filling the crucial gap in the assessment of the conservation status of T. hermanni.
Natural variation in HsfA2 pre‐mRNA splicing is associated with changes in thermotolerance during tomato domestication
Authors: Hu Yangjie , Mesihovic Anida , Jiménez‐Gómez José M. , Röth Sascha , Gebhardt Philipp , Bublak Daniela , Bovy Arnaud , Scharf Klaus‐Dieter , Schleiff Enrico , Fragkostefanakis Sotirios
Published: September 2019

Wild relatives of crops thrive in habitats where environmental conditions can be restrictive for productivity and survival of cultivated species. The genetic basis of this variability, particularly for tolerance to high temperatures, is not well understood. We examined the capacity of wild and cultivated accessions to acclimate to rapid temperature elevations that cause heat stress (HS).

We investigated genotypic variation in thermotolerance of seedlings of wild and cultivated accessions. The contribution of polymorphisms associated with thermotolerance variation was examined regarding alterations in function of the identified gene.

We show that tomato germplasm underwent a progressive loss of acclimation to strong temperature elevations. Sensitivity is associated with intronic polymorphisms in the HS transcription factor HsfA2 which affect the splicing efficiency of its pre‐mRNA. Intron splicing in wild species results in increased synthesis of isoform HsfA2‐II, implicated in the early stress response, at the expense of HsfA2‐I which is involved in establishing short‐term acclimation and thermotolerance.

We propose that the selection for modern HsfA2 haplotypes reduced the ability of cultivated tomatoes to rapidly acclimate to temperature elevations, but enhanced their short‐term acclimation capacity. Hence, we provide evidence that alternative splicing has a central role in the definition of plant fitness plasticity to stressful conditions.