bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of adsorption layers and elastic deformation on thin-film lubrication of circular contacts with non-Newtonian lubricants
Authors: Chu Li-Ming , Lin Jaw-Ren , Chang-Jian Cai-Wan
Published: February 2018

Purpose

The modified Reynolds equation for non-Newtonian lubricant is derived using the viscous adsorption theory for thin-film elastohydrodynamic lubrication (TFEHL) of circular contacts. The proposed model can reasonably calculate the phenomenon in the thin-film lubrication (TFL) unexplained by the conventional EHL model. The differences between classical EHL and TFEHL with the non-Newtonian lubricants are discussed.

Design/methodology/approach

The power-law lubricating film between the elastic surfaces is modeled in the form of three layers: two adsorption layers on each surface and one middle layer. The modified Reynolds equation with power-law fluid is derived for TFEHL of circular contacts using the viscous adsorption theory. The finite difference method and the Gauss–Seidel iteration method are used to solve the modified Reynolds equation, elasticity deformation, lubricant rheology equations and load balance equations simultaneously.

Findings

The simulation results reveal that the present model can reasonably calculate the pressure distribution, the film thickness, the velocity distribution and the average viscosity in TFL with non-Newtonian lubricants. The thickness and viscosity of the adsorption layer and the flow index significantly influence the lubrication characteristics of the contact conjunction.

Originality/value

The present model can reasonably predict the average viscosity, the turning point and the derivation (log film thickness vs log speed) phenomena in the TFEHL under constant load conditions.
Experiment and simulation of friction coefficient of polyoxymethylene
Authors: Xiong Xiaoshuang , Hua Lin , Wan Xiaojin , Yang Can , Xie Chongyang , He Dong
Published: February 2018

Purpose

The purposes of this paper include studying the friction coefficient of polyoxymethylene (POM) under a broad range of normal load and sliding velocity; developing a mathematical model of friction coefficient of POM under a broad range of normal loads and sliding velocities; and applying the model to dynamic finite element (FE) analysis of mechanical devices containing POM components.

Design/methodology/approach

Through pin-on-disc experiment, the friction coefficient of POM in different normal loads and sliding velocities is investigated; the average contact pressure is between 5 and 15 Mpa and the sliding velocity is from 0.05 to 0.9 m/s. A friction algorithm is developed and embedded in the FE model to simulate the friction of POM in different normal loads and sliding velocities.

Findings

The friction coefficient of POM against steel declines with the increase of normal loads when the contact pressure is between 5 and 15 Mpa. The friction coefficient of POM against steel increases markedly when the sliding velocity is between 0.05 and 0.15 m/s, it decreases sharply between 0.15-0.45 m/s and then it stabilizes at high sliding velocity between 0.45 and 0.9 m/s. The friction coefficient of POM in different working operations has a significant effect on contact stress and shear stress. The simulation data and experiment data of POM friction force fit very well; therefore, it can be concluded that the friction algorithm and FE model are accurate.

Originality/value

The friction coefficient of POM under a broad range of normal loads and sliding velocities is investigated. The friction coefficient model of POM is established as a function of normal loads and sliding velocities in the dry sliding condition. A friction algorithm is developed and embedded in the FE model of the friction of POM. The mathematical model of the friction coefficient accurately agrees with the experiment data, and simulation data and experiment data of the POM friction force fit very well.
Analysis of influencing factors on transient temperature field of wet clutch friction plate used in marine gearbox
Authors: Lin Tengjiao , Tan Zi-ran , He Ze-yin , Cao Hong , Lv He-sheng
Published: February 2018

Purpose

This paper aims to introduce the moment of inertia of the driving and driven end of the clutch into the analysis of the transient temperature field of a friction plate and studied the influencing factors on that, especially to a marine gearbox.

Design/methodology/approach

A three-dimensional transient heat transfer analysis model of a wet clutch friction plate used in a marine gearbox is developed, and the transient characteristics of the temperature field during engagement are analyzed with taking account of the influence factors such as the sliding friction coefficient, engaging revolving speed, moment of inertia and applied engagement pressure.

Findings

The paper found out that the hot spot appears on the surface of the friction plate, taking account of the effect of radial slots and spiral groove. To avoid damage to the friction plate as a result of overheating, the appropriate sliding friction coefficient, lower engaging revolving speed and reasonable selection of applied engagement pressure curve can ensure a favorable heating situation of the friction plate. The reasonable structural design for the clutch with a bigger moment of inertia of driving end and smaller moment of inertia of driven end can reduce the engaging time effectively and decrease the peak temperature of the friction plate.

Originality/value

This paper fulfils a method to study the transient temperature field of a wet clutch friction plate, especially used in a marine gearbox.
Effect of the bionic morphologies on bio-tribological properties of surface-modified layers on Ti6Al4V with Ni+/N+ implantation
Authors: Wang Yuan
Published: February 2018

Purpose

The main purpose of this study is to enhance bio-tribological properties of Ti6Al4V and the surface-modified layers of Ni+/N+-implanted Ti6Al4V alloy, bionic texturing was done on Ti6Al4V surface.

Design/methodology/approach

The phase compositions and nano-hardness of the surface-modified layers of the samples have been analyzed by X-ray diffractometer and Nano Indenter, respectively. This paper has conducted bio-tribological tests under artificial saliva, sodium hyalurate and sodium hyalurate +γ-globulin by micro tribology multifunction tribometer, with ZrO2 ball/modified layer as the friction pair. S-3000N scanning electron microscope has been used to analyze the morphology of the surface-modified layers and scratches of the ones after the bio-tribological tests.

Findings

The results show that the surface-modified layers were mainly composed of Ti2Ni and Ti2N. Moreover, bionic texturing can obviously increase the contents of Ti2Ni and Ti2N that were formed on the surface of Ni+/N+-implanted Ti6Al4V alloy, and enhance the nano-hardness of the surface-modified layers. It could also reduce the friction coefficients of the surface-modified layers, and render the modified layers more wear-resistant.

Originality/value

The surface bio-tribological properties of Ti6Al4V have been enhanced by ion implantation technique and bionic texturing in this paper; this provided a new method for the research of related fields.
Microstructure in the joining zone during the friction welding of the two dissimilar steels
Authors: Ratković Nada , Lazić Vukic , Arsić Dušan , Nikolić Ružica R. , Prokić Cvetković Radica , Popović Olivera
Published: February 2018

Purpose

The purpose of this paper is to point out the possibilities for friction welding of dissimilar steels which are used in various industries. In addition, friction welding is a welding method that is applied for executing the very responsible joints. This research is focused on friction and tribological processes in the friction plane of the two pieces during the welding.

Design/methodology/approach

The present study research has been conducted based on the experimental testing of cylindrical specimens and results are analyzed.

Findings

The austenite grain size is affected by several factors through the friction process phase and the compacting phase during the welding. The very fine grain is the consequence of the high degree of the plastic deformation of the near-the-contact layers even in the friction phase. The viscous layer, which is formed during the stable friction phase, is the area where the moving of matter occurs according to a very complex mechanism.

Originality/value

The paper contains useful results from the area of conventional friction welding of dissimilar steels and it can be very useful to researchers and engineers who deal with similar problems.
A solution considering elastic-plastic deformation of asperities for contact between rough cylindrical surfaces
Authors: Wen Yuqin , Tang Jin Yuan
Published: February 2018

Purpose

This paper aims to study the contact between rough cylindrical surfaces considering the elastic-plastic deformation of asperities.

Design/methodology/approach

The elastic deformation of the nominal surface of the curved surface is considered, the contact area is discretized by the calculus thought and then the nominal distance between two surfaces is obtained by iteration after the pressure distribution is assumed. On the basis of the Zhao, Maietta and Chang elastic-plastic model, the contact area and the contact pressure of the rough cylindrical surfaces are calculated by the integral method, and then the solution for the contact between rough cylindrical surfaces is obtained.

Findings

The contact characteristic parameters of smooth surface Hertz contact, elastic contact and elastic-plastic contact between rough cylindrical surfaces are calculated under different plastic indexes and loads, and the calculation results are compared and analyzed. The analysis shows that the solution considering the elastic-plastic deformation of asperities for the contact between rough cylindrical surfaces is scientific and rational.

Originality/value

This paper provides a new effective method for the calculation of the contact between rough cylindrical surfaces.
Islamic occasions and investor sentiment
Authors: Jaziri Marwa , Abdelhedi Mouna
Published: February 2018

Purpose

The purpose of this paper is to investigate whether the Islamic religious occasions can, through their impact on investor sentiment, affect returns in six Arab financial markets.

Design/methodology/approach

In this paper, the authors test the effect of the occasions of Hajj pilgrimage, Ramadan, Eid-al-Fitr, Mawlid and Ashura during the period of 2001-2016 on Saudi Arabia, Dubai, Kuwait, Egypt, Qatar and Bahrain financial markets. Three measures of investor sentiment are used: trading volume, high minus low and psychological line index.

Findings

Higher effect of investor sentiment on returns is detected after Hajj pilgrimage than that before Hajj pilgrimage in all studied financial markets. The positive emotions during Ramadan contribute significantly to the increase in returns in Arab financial markets. Results indicate that most of studied financial markets exhibit a significant effect of investor sentiment on returns during the first 10 days and the second 10 days of Ramadan. Empirical results indicate that Eid-al-Fitr affects the relation between investor sentiment and returns in Saudi Arabia, Kuwait, Qatar and Dubai financial markets. Relationship between investor sentiment and returns is not is not significantly affected by the Mawlid occasion, except in the Dubai and Kuwait financial markets.

Originality/value

The Islamic occasions of the Hajj pilgrimage, Ramadan and Eid-al-Fitr affect significantly the relation between investor sentiment and returns.
Predicting the growth of high-growth SMEs: evidence from family business firms
Authors: Megaravalli Amith Vikram , Sampagnaro Gabriele
Published: February 2018

Purpose

The purpose of this paper is to arrive at high-growth firm (HGF) and predict the growth of rapid-growth firms using the set of balance-sheet ratios.

Design/methodology/approach

The source of data came from the AIDA database, a commercial database provided by Bureau van Dijk. A total of 45,000 family business small- and medium-scale enterprises of Italy were selected for the study. Liquidity ratio, solvency ratio, firm age, cash flow, and working capital are considered as predictors of the firm growth. Probit regression is used for predicting the growth of the firms.

Findings

The result of the study indicated that the most important financial indicators were the liquidity ratio, solvency ratio, firm age, cash flow, and working capital are most important predictors of firm growth. The ROC of the model is 70.78, which shows that the model is fair.

Originality/value

The present study considers an innovative approach that considers balance sheet issued the year prior to the observation of rapid growth as predictors of firm growth (similar to the credit-scoring models, i.e. theZ-score model, to measure the probability of default).
Essay on spillovers from advanced economics (AE) to emerging economics (EM) during the global financial crisis
Authors: Akinsola Foluso Abioye
Published: February 2018

Purpose

The purpose of this paper is to estimate the bond market linkages between emerging markets (EM) and advanced markets (AM) yields by estimating yield equations for EMs as a function of AM yields and illustrating the quantitative macroeconomic effects on EMs of global yield shocks in a multi-country dynamic stochastic general equilibrium modeling model.

Design/methodology/approach

The research used a monthly sample of 45 advanced and EM economies covering the period 1998Q1 to 2010Q6. In this paper, the authors have shown that, indeed, there is a spillover effect from AD to EM countries and that most transmission channels, although they vary in significance, are all economically relevant. The main results of the paper underline the importance of international spillover across countries in the financial market. The strongest international transmission of shocks to EM is from the USA and the UK.

Findings

The authors find evidence that shocks in the volatility index and commodity fuels have a positive and significant impact on EM bond yield. Moreover, shocks in three-month US treasury bills, credit default swap, the London gold price and the Brent petrol price have a significant negative impact on EM bond yield. Finally, the result shows that global external shocks are found to be significant in determining bond yield and causing spillover into the EM.

Originality/value

These findings are especially important for policy makers in understanding the transmission of shocks in the bond market across different countries, as well as for risk management.
Modeling the impact of Basel III regulations on loan demand
Authors: Swamy Vighneswara
Published: February 2018

Purpose

The purpose of this study is to provide an econometric modeling of demand for bank credit and not only offer useful insights to the decision-makers in the public and private sector but also support researchers and analysts in recognizing the determinants of lending in a major dynamic economic context.

Design/methodology/approach

This study addresses the “supply-versus-demand-puzzle” by using a demand relationship and model loan demand as a function of interest rates and economic activity that may also capture supply effects. Loan demand modeled as a function of interest rates and economic activity not only represents a demand relationship but also captures supply effects. Using the generalized methods of moments estimation, the estimations are made robust to heteroskedasticity and/or autocorrelation of unknown form. GMM–Time series (HAC) option extends the robustness by using the weighting matrix that is robust to the contemporaneous correlation of unknown form to the autocorrelation of unknown form.

Findings

In a bank-dominated financial system like India, lending rates play a significant role in the transmission of monetary policy, as well as triggering and controlling loan demand and thereby exercising a pervasive effect on the output in the economy. The estimates indicate that the elasticity of loan demand is largely determined by the lending rate (0.6) and the economic activity (0.688). For one percentage point increase in capital ratio, the loan spread would rise by 31.4 basis points, which in turn would cause an increase of 18.8 basis points in loan demand assuming that risk-weighted assets are unchanged.

Originality/value

This is the first of its kind studying a banking system dominated emerging economy. Second, this study is based on a rich data set covering the period from 1979 to 2012, than other papers did, to capture the long-run association involving credit booms and busts and, thus, helps in avoiding the problem of estimation spanning the dominance of either boom or the bust alone. With a newer approach for quantification of the impacts of new regulatory standards, this study offers novel insights for the estimation of lending spreads.
Investigating the antecedents of work disengagement in the workplace
Authors: Aslam Usman , Muqadas Farwa , Imran Muhammad Kashif , Rahman Ubaid Ur
Published: February 2018

Purpose

Organizations are keenly interested to find out the causes of work disengagement that are harmful to achieve desired level of performance. Antecedents and levels of work disengagement vary across organizations and sectors due to differences in organizational culture. Therefore, the purpose of this paper is to determine the antecedents of work disengagement in the public sector organizations.

Design/methodology/approach

The research data were obtained from 303 employees of the public sector organizations using the self-administered questionnaires and cluster sampling technique. The research model proposed in this study has been examined by using the regression analysis and Hayes’s (2013) guidelines for moderation.

Findings

It is found that work disengagement increases because of managers’ personal preferences, unfairness, above the rule practices, negative political influence, work overload, and a lack of accountability in the workplace. The results reveal a positive association among organizational injustice, organizational politics, work overload, and work disengagement. Moreover, it is also found that organizational injustice is a strongest predictor of work disengagement. Bureaucratic culture of the public sector organizations has a strong strengthening effect on above-stated relationships.

Research limitations/implications

The study has identified various practical implications related to top management, employees, union, and researchers. The study provides new avenues for senior managers of the services sector to eradicate the levels of work disengagement by improving fairness and perception of organizational politics in the workplace.

Originality/value

There is rare literature that investigates the link between work disengagement and organizational injustice, organizational politics, and work overload especially in the presence of interactive effects of a bureaucratic culture. Most of the studies on employee disengagement did not use the unbiased and significant sample size so their results cannot be generalized to larger population. Therefore, the current study has aimed to overcome the shortcomings of previous studies and brings a novel conceptual model on work disengagement.
Use balanced scorecard for measuring competitive advantage of infrastructure assets of state-owned ports in Indonesia
Authors: Hamid Nurdjannah
Published: February 2018

Purpose

The purpose of this paper is to analyze the balanced scorecard (BSC) for measuring the competitive advantage of infrastructure assets of state-owned port in Indonesia: Pelindo IV, Makassar, Indonesia.

Design/methodology/approach

This investigation adopts an explanatory and exploratory qualitative case study method to analyze the effectiveness of the BSC over the strategy management processes. For data collection, the researchers used semi-structured interviews, direct observation and document collection. Data collection was made for a six-month period, which allowed deep knowledge to be gained of the culture and management methods used in Pelindo IV Makassar Branch. Other data collected refer to the company’s documentation and reporting of online media publications. Detailed interview data were the main data sources, allowing the authors to obtain a detailed and holistic understanding of the experience, opinions, and attitudes of the interviewees. Interviews focus on asset management to determine the relationship between various factors. This study adopts an ideal BSC principle (four perspectives) in order to develop a strategic map for infrastructure assets of Pelindo IV.

Findings

The results showed that the management performance of Pelindo IV in the financial sector over the next five years was expected to increase by 3.5 times with the business profit reaching an amount of Rp.1.64 trillium in 2017. In the next five years, the target of the customer’s perspective set was zero complaints and zero claim with waiting time meeting the ideal standard, which is a maximum of one-hour service, and the number of containers were expected to witness an average growth of 30 percent per year; the growth ship traffic visit history showed that the flow of goods increased by 4 percent and the number of passengers was targeted to grow up to 30 percent. A historical growth rate of 6 percent was also expected both for the human resources and personnel scout.

Originality/value

In this paper, the Sobel test was used to test the significance of a mediation effect and balanced scorecard was used for measuring competitive advantage of infrastructure assets of state-owned ports in Indonesia. Previously, no research has been undertaken to examine the relationship between the location of the study and competitive advantage of infrastructure assets in the context of PELINDO IV, Makassar branch, Indonesia.
Endozoochory of aquatic ferns and angiosperms by mallards in Central Europe
Authors: Lovas‐Kiss Ádám , Vizi Balázs , Vincze Orsolya , Molnár V. Attila , Green Andy J.
Published: February 2018

Modern literature on plant dispersal by birds focuses mainly on the importance of frugivory and scatter‐hoarding, yet recent studies show that endozoochory by migratory waterbirds is an important mechanism of long‐distance dispersal for a broad range of plants. Nevertheless, there is a lack of empirical field studies that identify the plants dispersed by waterbirds in a comprehensive manner. In particular, so far there are no detailed studies of the level of spatial variation in the plant taxa dispersed by a waterbird vector, and no clear demonstration that aquatic ferns can be dispersed by endozoochory. Consequently, we remain ignorant of the networks of dispersal interactions between granivorous waterbirds and plants.

Five sets of faecal samples (total n = 215) were collected from mallards Anas platyrhynchos on autumn migration in the Hevesi‐holm and Balaton regions in Hungary, central Europe. Intact diaspores were extracted, identified and their germinability assessed under standard conditions. The plant communities recorded at different sites were compared with PERMANOVA and other multivariate methods.

Macrospores of the floating watermoss Salvinia natans were recorded in 32 samples, and a total of 16 macrospores germinated, providing the first field demonstration of endozoochory of ferns by birds. Of 21 angiosperm taxa recorded (of which eight germinated), 13 were terrestrial species, although the most abundant taxa were aquatic species such as the alkali bulrush Bolboschoenus maritimus and the sago pondweed Potamogeton pectinatus. Two naturalized alien species, the common fig Ficus carica and the hackberry Celtis occidentalis were also recorded. Only four of the taxa had an endozoochory syndrome. The plant taxa dispersed varied at two different spatial scales, with minor but significant differences between samples from sites separated by less than 1 km, and major differences between the two regions separated by c. 220 km.

Synthesis. This is a unique study of the spatial variation in plants dispersed by endozoochory by a migratory waterfowl species, with a high taxonomic resolution and the first demonstration of avian endozoochory of ferns. We recorded eight taxa not previously reported as dispersed by mallards, showing how more empirical studies are essential, so we can understand which plants are dispersed by migratory birds. We found evidence that networks of interactions between granivorous waterbird vectors and dispersed plants vary spatially.
Divergent monetary policies and international dollar credit: Evidence from bank‐level data
Authors: He Dong , Wong Eric , Ho Kelvin , Tsang Andrew
Published: February 2018

This paper uses a comprehensive and detailed bank‐level data set to study how the divergence of central bank balance sheet policy in the US vis‐à‐vis the euro area and Japan would affect the supply of international US dollar loans by global banks. Our empirical findings support the view that the contractionary effect of US monetary normalization on global dollar liquidity would be offset by an expansionary effect from continued supply of US dollar loans by euro area and Japanese banks. The net effect, however, is crucially dependent on the stability of global foreign exchange markets and investor perceptions of the default risks of global banks. Our findings show that there could be a significant contraction of the supply of international US dollar loans if and when the US monetary normalization coincides with a dislocation of the FX swap market and a rise of bank default risks. Our results are robust to alternative model specifications and different data sets.
Special education advocacy among culturally and linguistically diverse families
Authors: Burke Meghan M. , Goldman Samantha E.
Published: February 2018

As the field of special education advocacy grows and the population of students with disabilities in the United States becomes more diverse, it is crucial to understand how advocates work with culturally and linguistically diverse (CLD) families of individuals with disabilities. In this pilot study, we conducted interviews with twelve CLD advocates who worked primarily with CLD families. We found that CLD advocates faced barriers and supports in connecting with families as well as in working with families and schools. Advocates reported meeting families through informal networks. When working with families, advocates reported supports (e.g., shared cultural, parenting and family experiences) and barriers (e.g., disempowerment and limited access to education and resources). When working within the school, advocates reported two barriers: language and a deficit‐based perspective. Implications for policy and practice are discussed.
How Can West African Rice Compete in Urban Markets? A Demand Perspective for Policymakers
Authors: Fiamohe Rose , Demont Matty , Saito Kazuki , Roy‐Macauley Harold , Tollens Eric
Published: February 2018

In West Africa, rice produced locally falls short of meeting the demand and preferences of urban consumers. We analyzed the challenges facing local rice in urban markets and identified policies that can be implemented to improve the competitiveness of the regional rice sector. We argue that without addressing the demand side of the value chain, efforts on the supply side might fall short in reducing import dependency. Evidence suggests that while imported rice has easy access to urban markets, local rice faces more challenges in reaching urban consumers. The low market share of local rice in urban markets is in part due to consumers’ dislike of local rice as it is perceived as being of inferior quality relative to imported rice. Local rice also tends to fetch lower prices. The experimental studies reviewed suggest, however, that urban consumers are willing to pay price premiums for local rice if its quality is upgraded. We propose a two‐stage policy sequence: (i) encouraging investment in quality upgrading; (ii) gradually increasing the Common External Tariff (CET) from 10 to 35 per cent to increase cost‐competitiveness of West African rice relative to imported rice. To stabilise and finance the sector, we further advocate the establishment of a flat‐rate levy on the value of rice imports.
Do predictors of smoking relapse change as a function of duration of abstinence? Findings from the United States, Canada, United Kingdom and Australia
Authors: Yong Hua‐Hie , Borland Ron , Cummings K. Michael , Partos Timea
Published: February 2018

Aims

To estimate predictors of time to smoking relapse and test if prediction varied by quit duration.

Design

Longitudinal cohort data from the International Tobacco Control Four‐Country survey with annual follow up collected between 2002 and 2015.

Setting

Canada, United States, United Kingdom and Australia.

Participants

A total of 9171 eligible adult smokers who had made at least one quit attempt during the study period.

Measurements

Time to relapse was the main outcome. Predictor variables included pre‐quit baseline measures of nicotine dependence, smoking and quitting‐related motivations, quitting capacity and social influence, and also two post‐quit measures, use of stop‐smoking medications and quit duration (1–7 days, 8–14 days, 15–31 days, 1–3 months, 3–6 months, 6–12 months, 1–2 years and 2+ years), along with socio‐demographics.

Findings

All factors were predictive of relapse within the first 6 months of quitting but only wanting to quit, quit intentions and number of friends who smoke were still predictive of relapse in the 6–12‐month period of quitting [hazard ratios (HR) = 1.20, P < 0.05; 1.13, P < 0.05; and 1.21, P < 0.001, respectively]. Number of friends smoking was the only remaining predictor of relapse in the 1–2 years quit period (HR = 1.19, P = 0.001) with none predictive beyond the 2‐year quit period. Use of stop‐smoking medications during quit attempts was related negatively to relapse during the first 2 weeks of quitting (HR = 0.71–0.84), but related positively to relapse in the 1–6‐month quit period (HR = 1.29–1.54). Predictive effects of all factors showed significant interaction with quit duration except for perceiving smoking as an important part of life, prematurely stubbing out a cigarette and wanting to quit.

Conclusions

Among adult smokers in the United States, Canada, United Kingdom and Australia, factors associated with smoking relapse differ between the early and later stages of a quit attempt, suggesting that the determinants of relapse change as a function of abstinence duration.
Connections and Context in Finance Research
Authors: Harford Jarrad
Published: February 2018

In this paper, I discuss my view of how research in corporate finance has, over time, added more context to our study of corporate activities. This has involved progressively moving from seminal event studies that provided the unconditional price response to an event, to using firm characteristics to condition the response, to industry and eventually network effects. I emphasize the potential of network analysis to substantially increase our understanding of the motivations, implications, and value effects of corporate activities. I further point to examples in the literature where this has been successful and provide some thoughts on future directions.
Development and validation of the mastocytosis activity score
Authors: Siebenhaar F. , Sander B. , Ho L. H. T. , Ellrich A. , Maurer M. , Weller K.
Published: February 2018

Background

Mastocytosis is a heterogeneous disease characterized by a clonal expansion of mast cells in various organs. The vast majority of patients suffer from signs and symptoms caused by mediator release from mast cells. Although the disease burden is high, there is currently no specific and validated instrument to measure and monitor signs and symptoms in patients with mastocytosis.

Objective

To develop and validate a disease‐specific tool to measure and monitor the activity of signs and symptoms in patients with mastocytosis, the Mastocytosis Activity Score (MAS).

Methods

Nineteen potential MAS items were developed in a combined approach consisting of semi‐structured patient interviews, expert input and literature research. Item selection was performed by impact analysis with 76 patients followed by a review for face validity. The resulting MAS was tested for validity, reliability and influence factors. In parallel, a US American English version of the MAS was developed.

Results

A total of 68 mastocytosis patients took part in the MAS validation study. The final 9‐item MAS was found to have a three‐domain structure (“skin,” “gastrointestinal tract” and “other”), a valid total score and an excellent test‐retest reliability. Multiple regression analysis revealed that disease duration, age or gender is not a significant determinant of the MAS results.

Conclusions

The MAS is a disease‐specific, valid and reliable patient‐reported outcome measure for adult patients with cutaneous and indolent systemic mastocytosis. It may serve as a valuable tool to measure and monitor mastocytosis activity, both, in clinical trials and in routine care.
Do substantial BMI reduction episodes among Swedish schoolchildren have any impact on their final height?
Authors: Nilsen Bente B. , Yngve Agneta , Werner Bo
Published: February 2018

Aim

This study investigated whether substantial body mass index (BMI) reductions in Swedish schoolchildren aged seven years to 19 years, caused by disease, healthy or unhealthy behaviour, had any impact on their final height.

Methods

We used height and weight data on 6572 subjects from two nationally representative longitudinal samples of Swedish children born in 1973 and 1981. These provided information on their final height and any BMI reduction episodes.

Results

Of the 6572 subjects (50.9% boys), among individuals with information on final height, 1118 had a BMI reduction of 5% and <10%, and 346 had at least one substantial BMI reduction of 10% or more. On a group level, there was no statistically significant difference in the final height of individuals with BMI reductions of 10% or more and those without. The findings were independent of age and the subject's BMI at the start of the reduction episode. However, there were a number of cases where a substantial BMI reduction probably had an impact on the subject's final height.

Conclusion

Our study found no evidence that a substantial BMI reduction had any impact on final height on a group level, but further analyses of specific case studies are necessary to determine whether substantial BMI reduction might have an impact on final height.
Using anaerobic blood cultures for infants younger than 90 days rarely showed anaerobic infections but increased yields of bacterial growth
Authors: Gross Itai , Gordon Oren , Benenson Shmuel , Abu Ahmad Wiessam , Shimonov Amir , Hashavya Saar , Eventov‐Friedman Smadar
Published: February 2018

Aim

The use of anaerobic blood cultures in infants suspected of bacteraemia is controversial. Our children's hospital uses both aerobic and anaerobic media, regardless of the risk of anaerobic infection, and the aim of this study was to re‐evaluate the use of anaerobic cultures in infants.

Methods

We collected retrospective data from 2002 to 2016 on all blood cultures taken from infants younger than 90 days in the Hadassah‐Hebrew University Medical Centre, Jerusalem, Israel. The incidence and characteristics of infants with positive anaerobic blood cultures were assessed.

Results

During the study period, 51 035 blood cultures were drawn from 44 304 infants. Of these, 1496 (2.9%) were clinically significant positive cultures. Pathogenic obligatory anaerobic bacteraemia was extremely rare, with only 37 positive cultures (0.07%) from all of the cultures drawn. No specific risk factors for obligatory anaerobic bacteraemia could be defined, but as many as 174 (11.6%) clinically significant isolates were only detected in the anaerobic culture bottle.

Conclusion

True anaerobic bacteraemia was extremely rare in neonates. Nevertheless, using anaerobic culture media may increase the overall yield of bacterial culture growth by isolating anaerobic‐facultative bacteria. This should be weighed up against increasing the volume of blood used for the aerobic culture.
Corticotropin‐releasing factor receptor 2‐deficiency eliminates social behaviour deficits and vulnerability induced by cocaine
Authors: Morisot Nadège , Monier Romain , Le Moine Catherine , Millan Mark J , Contarino Angelo
Published: February 2018

Background and Purpose

Poor social behaviour and vulnerability to stress are major clinical features of stimulant use disorders. The corticotropin‐releasing factor (CRF) system mediates stress responses and might underlie substance use disorders; however, its involvement in social impairment induced by stimulant substances remains unknown. CRF signalling is mediated by two receptor types, CRF1 and CRF2. In the present study we investigated the role of the CRF2 receptor in social behaviour deficits, vulnerability to stress and related brain alterations induced by cocaine administration and withdrawal.

Experimental Approach

CRF2 receptor‐deficient (CRF2−/−) and littermate wild‐type mice were repeatedly tested in the three‐chamber task for sociability (i.e. preference for an unfamiliar conspecific vs. an object) and social novelty preference (SNP; i.e. preference for a novel vs. a familiar conspecific) before and after chronic cocaine administration. An in situ hybridization assay was used to assess gene expression of the stress‐responsive arginine vasopressin (AVP) and oxytocin (OT) neuropeptides in the hypothalamus.

Key Results

CRF2 receptor deficiency eliminated the sociability deficit induced by cocaine withdrawal. Moreover, CRF2−/− mice did not show either the stress‐induced sociability deficit or the increased AVP and OT expression associated with long‐term cocaine withdrawal, indicating resilience to stress. Throughout, wild‐type and CRF2−/− mice displayed SNP, suggesting that cocaine withdrawal‐induced sociability deficits were not due to impaired detection of social stimuli.

Conclusions and Implications

These findings demonstrate a central role for the CRF2 receptor in social behaviour deficits and biomarkers of vulnerability induced by cocaine withdrawal, suggesting new therapeutic strategies for stimulant use disorders.
Environmental peanut exposure increases the risk of peanut sensitization in high‐risk children
Authors: Brough H. A. , Kull I. , Richards K. , Hallner E. , Söderhäll C. , Douiri A. , Penagos M. , Melén E. , Bergström A. , Turcanu V. , Wickman M. , Lack G.
Published: February 2018

Background

High household peanut consumption is associated with the development of peanut allergy, especially when peanut allergic cases are compared against atopic controls; thus, environmental peanut exposure (EPE) may be a risk factor for peanut sensitization and allergy. In this study, we explored the relationship between EPE and school‐age peanut sensitization in a population‐based cohort.

Methods

Maternal bed dust was collected postnatally, and EPE was quantified using a polyclonal peanut ELISA. Peanut sensitization was assessed by specific IgE to peanut extract and sIgE to peanut protein component allergens Ara h 1, 2 or 3 ≥ 0.35kU/L (primary peanut sensitization). Initial nested case‐control analysis was performed comparing peanut‐sensitized cases against high‐risk controls (matched for parental atopy) (n = 411) using a conditional regression analysis. This was followed by whole cohort analysis (n = 1878) comparing EPE against peanut sIgE sensitization at ages 4 and 8 years using generalized estimating equations and against primary peanut sensitization at age 8 years using a logistic regression model. Finally, a subgroup analysis was performed comparing the impact of EPE in peanut‐sensitized vs egg‐sensitized, peanut‐tolerant individuals using logistic regression analysis. Levels of EPE were compared between groups using the Mann‐Whitney U test.

Results

In the nested case‐control analysis, a higher level of EPE around birth was associated with peanut‐specific IgE sensitization at age 4 years (OR=1.41, 95% CI:1.05‐1.90) and primary peanut sensitization at age 8 years (OR=2.11, 95% CI:1.38‐3.22) compared against high‐risk controls. When the whole BAMSE cohort was assessed, EPE was no longer associated with peanut sensitization; however, on subgroup analysis, EPE was associated with primary peanut sensitization when compared against egg‐sensitized peanut‐tolerant controls with an adjusted odds ratio of 1.44 per unit EPE (95% CI:1.06‐1.94). There was no significant interaction between EPE and FLG loss‐of‐function mutations, egg sensitization at age 4 years, infantile eczema or parental atopy on peanut sensitization.

Conclusions

Higher levels of environmental exposure to peanut in the first few months of life appear to increase the probability of developing school‐age peanut sensitization in atopic children (based on egg sensitization and parental atopy).
A triglyceride-rich lipoprotein environment exacerbates renal injury in the accelerated nephrotoxic nephritis model
Authors: Saja M F , Cook H T , Ruseva M M , Szajna M , Pickering M C , Woollard K J , Botto M
Published: February 2018

Hyperlipidaemia accompanies chronic renal disease either as a consequence of the renal dysfunction or as part of generalized metabolic derangements. Under both situations, the lipid profile is characterized by accumulation of triglyceride-rich lipoproteins (TGRLs). This lipid profile is recognized as a risk factor for cardiovascular complications. Whether it may pose a risk for renal injury as well remains unclear. A hyper-TGRL state was generated in C57BL/6 mice using poloxamer-407 (P-407) and immune complex-mediated renal injury was triggered using the accelerated nephrotoxic nephritis (ANTN) model. The hyper-TGRL animals were hypersensitive to ANTN demonstrated by greater haematuria and glomerular cellularity. These changes were accompanied by increased glomerular accumulation of CD68+ macrophages. The hypersensitive response to ANTN was not seen in low-density lipoprotein receptor knock-out mice fed with a high fat diet, where triglyceride levels were lower but cholesterol levels comparable to those obtained using P-407. These data indicate that a hyper-TGRL state might be more detrimental to the kidneys than low-density lipoprotein-driven hypercholesterolaemia during immune complex-mediated nephritis. We speculate that the hyper-TGRL environment primes the kidney to exacerbated renal damage following an inflammatory insult with increased accumulation of macrophages that may play a key role in mediating the injurious effects.
Metastatic melanoma with dedifferentiation and extensive rhabdomyosarcomatous heterologous component
Authors: Campbell Katelynn , Kumarapeli Asangi R. , Gokden Neriman , Cox Roni M. , Hutchins Laura , Gardner Jerad M.
Published: February 2018

Melanoma may undergo dedifferentiation and sarcomatous transformation with loss of melanocytic markers. Dedifferentiated melanoma rarely forms true rhabdomyoblasts with skeletal muscle immunophenotype (rhabdomyosarcomatous heterologous component). A 52‐year‐old woman was diagnosed with invasive melanoma (Breslow thickness 0.83 mm) of the upper back in 2012, treated by wide local excision only. In 2013, an axillary mass was excised to show metastatic melanoma with 2 morphologies: an epithelioid morphology expressing S100 and MART‐1 and a spindled morphology with loss of melanocytic markers but strong expression of desmin. This metastasis was found to have BRAF V600E mutation. In 2015, a thoracic epidural mass biopsy showed atypical spindle cells with focal HMB‐45 but essentially no S100 expression. Numerous rhabdomyoblasts, some with striations that were strongly positive for desmin and myogenin, were present. In 2016, a right nephrectomy was performed for metastasis to the kidney, and showed sheets of spindle cells and rhabdomyoblasts expressing desmin and myogenin but not S100. Only focal areas demonstrated expression of HMB‐45 and SOX‐10, supporting the melanocytic origin of the tumor. The numerous rhabdomyoblasts and the loss of S100 expression in the metastatic lesions in this case could have easily led to misdiagnosis if the clinical history was not known.
One explanation to rule them all? Identifying sub‐groups of non‐drinking Swedish ninth graders
Authors: Raninen Jonas , Livingston Michael , Karlsson Patrik , Leifman Håkan , Guttormsson Ulf , Svensson Johan , Larm Peter
Published: February 2018

Introduction and Aims

Researchers in a number of countries have recently identified major changes in adolescent alcohol consumption since the early 2000s, with the prevalence of teenage drinking more than halving in some countries. The major aims of the current study are to examine if there are sub‐groups among non‐drinking Swedish ninth graders and to describe how the prevalence of these groups has changed during the period 1999 to 2015.

Design and Methods

Data from five waves of the Swedish European School Survey Project on Alcohol and other Drugs study was used. The data covered 16 years and the total sample comprised 14 976 students. Latent class analysis was used to identify sub‐groups of non‐drinkers (n = 4267) based on parental approval towards drinking, parental monitoring, leisure time activities, school performance and use of other substances.

Results

Five latent classes were found: computer gamers (8.3%), strict parents (36.5%), liberal parents (27.0%), controlling but liberal parents (16.6%) and sports (11.6%). In the non‐drinking sub‐group the strict parents group increased most between 1999 and 2015.

Discussion and Conclusions

The results imply that there is notable within‐group diversity in non‐drinking youth. Several mechanisms and explanations are thus likely to be behind the decline in drinking participation among Swedish adolescents.
Intravenous fentanyl use among people who inject drugs in Australia
Authors: Geddes Louise , Iversen Jenny , Memedovic Sonja , Maher Lisa
Published: February 2018

Introduction and Aims

There is a current epidemic of pharmaceutical opioid (PO) misuse, particularly fentanyl and fentanyl analogues, globally. Fentanyl is a highly potent synthetic opioid with rapid onset and significantly higher risk of overdose compared with other opioids. Contexts and correlates of fentanyl use among people who inject drugs (PWID) in Australia are under‐researched.

Design and Methods

The Australian Needle Syringe Program Survey is conducted annually. Consenting PWID complete a self‐administered questionnaire and provide a capillary dried blood spot for human immunodeficiency virus and hepatitis C virus antibody testing. Bivariate and multivariate logistic regressions determined correlates of recent (last 6 months) fentanyl injection in 2014.

Results

Recent fentanyl injection was reported by 8% (n = 193) of the total sample. Among the 848 PWID who recently injected POs, 23% injected fentanyl. Compared with PO injectors who had not injected fentanyl, those who had injected fentanyl were significantly more likely to identify as Indigenous Australian [adjusted odds ratio (AOR) 1.61; 95% confidence interval (CI) 1.04, 2.51; P = 0.034], inject daily or more frequently (AOR 1.92; 95% CI 1.30, 2.83; P = 0.005), inject in public (AOR 1.43; 95% CI 1.01, 2.02; P = 0.042) and to have overdosed in the past year (AOR 2.16; 95% CI 1.48, 3.13; P < 0.001), but were significantly less likely to receptively share syringes (AOR 0.56; 95% CI 0.36, 0.87; P = 0.010).

Discussion and Conclusions

Fentanyl injectors in Australia are significantly more likely to identify as Indigenous, report frequent injection, inject in public and experience overdose. Increased access to harm reduction interventions, including naloxone distribution, wheel filters and supervised injection facilities, are likely to benefit this population.