bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct risk factors and cost performance of road projects in developing countries
Authors: Ogbu Chukwuemeka Patrick , Adindu Chinedu Chimdi
Published: September 2019

Purpose

Globally, road projects are notorious for riskiness, which often results in cost overruns. In developing countries, these risks are amplified by economic instabilities and institutional failures. Majority of road projects in these countries are awarded to notedly inept indigenous contractors. Currently, research on the relationship between risks and cost performance of road projects has predominantly focussed on the client’s perspective. Effects of risks on contractors’ cost performance (profit) are inadequately investigated in literature. The purpose of this paper is to determine the relationship between direct risks and cost performance of road projects by indigenous contractors of developing countries from the contractors’ perspective.

Design/methodology/approach

The multivariate structural equation modelling technique was used to analyse purposively obtained data from indigenous contractors that recently completed road projects in Nigeria.

Findings

It was observed that a significant positive relationship exists between the aggregate project risk, i.e. project risk index of cost (PRIC) and cost performance of the projects. Significant positive relationships were also found to exist between identified cost risk centres and PRIC and between risk factors and cost risk centres. The risk centre site environment and location contributes the most to PRIC.

Research limitations/implications

Indigenous contractors of developing countries are to analyse the identified risk factors and centres prior to bidding for road projects and carefully manage them during project execution.

Originality/value

Future studies of risks in road project should aim to obtain project risk indices of costs for the projects.
Interaction of multiple cracks in a nonhomogeneous piezoelectric rectangular plane under an electromechanical loading
Authors: Kafaei Keyvan , Bagheri Rasul
Published: September 2019

Purpose

In accord with the literature reviews, there is not a promising examination regarding the several straight and curved cracks interaction with arbitrary arrangement in the rectangular FGP plane. The purpose of this paper is to consider the effect of crack length, position of the point load, material non-homogeneity constant and also the arrangement of cracks on the resulting field intensity factors.

Design/methodology/approach

First of all, in order to obtain a set of Cauchy singular integral equations, both the dislocation method and the finite Fourier cosine transform technique are applied. Using the corresponding solution to these equations, the dislocation densities on the crack surfaces are then obtained. Considering the results, both the stress intensity factors (SIFs) and electric displacement intensity factors (EDIFs) for a vertical crack and the interaction between two straight and curved cracks, which have an arbitrary configuration, are determined.

Findings

The numerical examples are represented in order to illustrate the interesting mechanical and electrical coupling phenomena induced by multi-crack interactions. At the end, the effects of the material non-homogeneity constant, the crack length and the cracks arrangements on the SIFs and EDIFs are investigated.

Originality/value

The solutions are obtained in series expansion forms which may be considered as Green’s functions in an FGP rectangular plane possessing multiple cracks. The technique of Green’s function provides the ability to analyze multiple cracks having any smooth configuration.
MHD flow and heat transfer analysis of Newtonian and non-Newtonian nanofluids due to an inclined stretching surface
Authors: Nandeppanavar Mahantesh M. , Srinivasulu T. , Bandari Shanker
Published: September 2019

Purpose

The purpose of this paper is to study the flow, heat and mass transfer of MHD Casson nanofluid due to an inclined stretching sheet using similarity transformation, the governing PDE’S equations of flow, heat and mass transfer are converted into ODE’S. The resulting non-linear ODE’S are solved numerically using an implicit finite difference method, which is known as Kellor-box method. The effects of various governing parameters on velocity, temperature and concentration are plotted for both Newtonian and non-Newtonian cases. The numerical values of skin friction, Nusselt number and Sherwood number are calculated and tabulated in various tables for different values of physical parameters. It is noticed that the effect of angle of inclination enhances the temperature and concentration profile whereas velocity decreases. The temperature decreases due to the increase in the parametric values of Pr and Gr due to thickening in the boundary layer.

Design/methodology/approach

Numerical method is applied to find the results.

Findings

Flow and heat transfer analysis w.r.t various flow and temperature are analyzed for different values of the physical parameters.

Research limitations/implications

The numerical values of skin friction, Nusselt number and Sherwood number are calculated and tabulated in various tables for different values of physical parameters.

Practical implications

The study of the boundary layer flow, heat and mass transfer is important due to its applications in industries and many manufacturing processes such as aerodynamic extrusion of plastic sheets and cooling of metallic sheets in a cooling bath.

Originality/value

Here in this paper the authors have investigated the MHD boundary layer flow of a Casson nanofluid over an inclined stretching sheet along with the Newtonian nanofluid as a limited.
Effects of rotation, voids and diffusion on characteristics of plane waves in a thermoelastic material
Authors: Singh Baljeet , Singla Himanshu
Published: September 2019

Purpose

The purpose of this paper is to study the effects of rotation, voids and diffusion on characteristics of plane waves in a thermoelastic material.

Design/methodology/approach

Lord and Shulman generalization of linear thermoelasticity is used to study the plane waves in a rotating thermoelastic material with voids and diffusion. The thermoelastic solid is rotating with a uniform angular velocity. The problem is specialized in two dimensions to study wave propagation. The plane harmonic solutions of governing field equations in a plane are obtained.

Findings

A velocity equation is obtained which indicates the propagation of five coupled plane waves in the medium. Reflection of an incident plane wave from stress-free surface of a half-space is also considered to obtain the amplitude ratios of various reflected waves. A numerical example is considered to illustrate graphically the effects of rotation, frequency, void and diffusion parameters on speeds and amplitude ratios of plane waves.

Originality/value

The present problem covers the combined effects of rotation, voids and diffusion on characteristics of plane waves in linear thermoelastic material in the context of Lord and Shulman (1967) and Aouadi (2010) theories, which are not studied in literature yet.
Analysis of activation energy in quadratic convective flow of a micropolar fluid with chemical reaction and suction/injection effects
Authors: RamReddy C. , Naveen P.
Published: September 2019

Purpose

The purpose of this paper is to analyze the combined effects of thermal radiation and activation energy with a chemical reaction on the quadratic convective flow of a micropolar fluid over an inclined plate. Convective thermal boundary condition and suction/injection effects are considered at the surface of an inclined plate.

Design/methodology/approach

The convection along with nonlinear Boussinesq approximation (i.e. quadratic convection or nonlinear convection) and usual boundary layer assumptions is employed in the mathematical formulation. Highly coupled nonlinear governing equations are tackled by a combined local non-similarity and successive linearization techniques.

Findings

The behavior of various pertinent parameters on the fluid flow characteristics is conferred through graphs and it reveals that the qualitative behaviors of velocity, temperature, skin friction and heat transfer rates of a micropolar fluid are similar for Biot number and radiation parameters. The suction/injection and activation energy parameters increase the concentration of the micropolar fluid within the boundary layer, while the chemical reaction parameter reduces the concentration in the same region. Further, this quadratic convection shows a strong influence on the fluid flow characteristics and then the impact of pertinent parameters is more prominent on the physical quantities, compared therewith results of the linear convection.

Practical implications

This kind of investigation is useful in the mechanism of combustion, aerosol technology, high-temperature polymeric mixtures and solar collectors which are operated at moderate to very high temperatures.

Originality/value

This attempt is a unique contribution to the establishment of both micropolar fluid and activation energy. This kind of study even in the absence of quadratic convection is not yet noted.
A study on relevance of second hand clothing retailing in Ethiopia
Authors: Khurana Karan , Tadesse Ruth
Published: September 2019

Purpose

This paper aims to highlight the relevance of second-hand clothing (SHC) in the Ethiopian textile and apparel value chain by investigating its potential and establishing a connect to sustainability from a consumption point of view.

Design/methodology/approach

Primary and secondary methods of research were used in this research. Structured observational technique was used to identify the retailers in the city. In total, 70 retailers of SHC were identified and 15 big size retailers were interviewed with open end questions through judgment sampling method.

Findings

From the analysis of the field research and scientific literature, the authors strongly believe that SHC has an important space in the consumer retail segment of the country. This trade remains in the shadow but is sustaining livelihoods of citizens. The SHC trade provides an automatic balance to the future excessive consumption which is a result of mass production and hence should be encouraged further on various dimensions.

Originality/value

Existing literature exhibits statistics of the trade and impact in East African Community (EAC) missing out on Ethiopia as it is not a member of the EAC. Moreover a connection of SHC to sustainability established has never been established in the past for under-developing countries, and it is one of the critical factors in the success of used clothing and future of textile and apparel business. This research also provides channelized solutions to the business for smooth implementation of SHC in Ethiopia and other under-developing countries.
Camera signal dependencies within coaxial melt pool monitoring in laser powder bed fusion
Authors: Kolb Tobias , Elahi Reza , Seeger Jan , Soris Mathews , Scheitler Christian , Hentschel Oliver , Tremel Jan , Schmidt Michael
Published: September 2019

Purpose

The purpose of this paper is to analyse the signal dependency of the camera-based coaxial monitoring system QMMeltpool 3D (Concept Laser GmbH, Lichtenfels, Germany) for laser powder bed fusion (LPBF) under the variation of process parameters, position, direction and layer thickness to determine the capability of the system. Because such and similar monitoring systems are designed and presented for quality assurance in series production, it is important to present the dominant signal influences and limitations.

Design/methodology/approach

Hardware of the commercially available coaxial monitoring QMMeltpool 3D is used to investigate the thermal emission of the interaction zone during LPBF. The raw images of the camera are analysed by means of image processing to bypass the software of QMMeltpool 3D and to gain a high level of signal understanding. Laser power, scan speed, laser spot diameter and powder layer thickness were varied for single-melt tracks to determine the influence of a parameter variation on the measured sensory signals. The effects of the scan direction and position were also analysed in detail. The influence of surface roughness on the detected sensory signals was simulated by a machined substrate plate.

Findings

Parameter variations are confirmed to be detectable. Because of strong directional and positional dependencies of the melt-pool monitoring signal a calibration algorithm is necessary. A decreasing signal is detected for increasing layer thickness. Surface roughness is identified as a dominating factor with major influence on the melt-pool monitoring signal exceeding other process flaws.

Research limitations/implications

This work was performed with the hardware of a commercially available QMMeltpool 3D system of an LPBF machine M2 of the company Concept Laser GmbH. The results are relevant for all melt-pool monitoring research activities connected to LPBF, as well as for end users and serial production.

Originality/value

Surface roughness has not yet been revealed as being one of the most important origins for signal deviations in coaxial melt-pool monitoring. To the best of the authors’ knowledge, the direct comparison of influences because of parameters and environment has not been published to this extent. The detection, evaluation and remelting of surface roughness constitute a plausible workflow for closed-loop control in LPBF.
Fused deposition modelling: a review
Authors: Vyavahare Swapnil , Teraiya Soham , Panghal Deepak , Kumar Shailendra
Published: September 2019

Purpose

Fused deposition modelling (FDM) is the most economical additive manufacturing technique. The purpose of this paper is to describe a detailed review of this technique. Total 211 research papers published during the past 26 years, that is, from the year 1994 to 2019 are critically reviewed. Based on the literature review, research gaps are identified and the scope for future work is discussed.

Design/methodology/approach

Literature review in the domain of FDM is categorized into five sections – (i) process parameter optimization, (ii) environmental factors affecting the quality of printed parts, (iii) post-production finishing techniques to improve quality of parts, (iv) numerical simulation of process and (iv) recent advances in FDM. Summary of major research work in FDM is presented in tabular form.

Findings

Based on literature review, research gaps are identified and scope of future work in FDM along with roadmap is discussed.

Research limitations/implications

In the present paper, literature related to chemical, electric and magnetic properties of FDM parts made up of various filament feedstock materials is not reviewed.

Originality/value

This is a comprehensive literature review in the domain of FDM focused on identifying the direction for future work to enhance the acceptability of FDM printed parts in industries.
Environmental life cycle analysis of a fixed PV energy system and a two-axis sun tracking PV energy system in a low-energy house in Turkey
Authors: Aksoy Tırmıkçı Ceyda , Yavuz Cenk
Published: September 2019

Purpose

The purpose of this paper is to propose a fixed PV energy system design and a sun tracking PV energy system design to meet the primitive energy demands of a typical house in Sakarya, Turkey with energy payback times (EPBT) and greenhouse payback times (GPBT) calculations.

Design/methodology/approach

The designs were developed based on the total solar radiation received on the surface of the PV modules. The EPBT and the GPBT of the designs were investigated by utilizing the current embodied energy data of the literature and annual energy output of the proposed systems. The monthly mean total solar radiation, the yearly total solar radiation and the annual energy output of the systems were calculated according to the results of previous studies of authors on 80-W prototypes of a fixed PV energy system tilted at the yearly optimum tilt angle of Sakarya and a two-axis sun tracking PV energy system.

Findings

The annual energy outputs of the fixed system and the tracking system were established to be 10.092 and 10.311 MJ, respectively. EPBT of the systems were estimated 15.347 years for the fixed system and 11.932 years for the tracking systems which were less than the lifespan of PV modules. The greenhouse gas emitted to produce and install the systems were estimated to be 6,899.342 kg for the fixed system and 5,040.097 kg for the tracking system. GPBT of the systems were calculated to be 5.203 and 2.658 years, respectively.

Originality/value

PV energy is clean without greenhouse gas emission during the operation. However, significant emissions occur in the life cycle of PV modules until the installation is completed. Therefore reducing the number of PV modules make great differences in the GPBT of PV energy systems. In this paper, comparisons between the GPBT results of the optimally tilted fixed system and tracking system were performed to discuss the best option by means of environmental concerns.
The dynamic relationship between CO2emission, international tourism and energy consumption in Pakistan: a cointegration approach
Authors: Liu Yaping , Kumail Tafazal , Ali Wajahat , Sadiq Farah
Published: September 2019

Purpose

The present study aims to investigate the dynamic relationship between international tourist receipts, economic growth, energy use and carbon dioxide (CO2) emissions in Pakistan over the period 1980-2016. Many researchers have investigated the link between tourism and CO2emissions, but there is no clear picture as the results are contradictory. This study is an attempt to compliment the literature related to tourism and environmental quality.

Design/methodology/approach

The study adopted the autoregressive distributed lagged (ARDL) model to investigate the short- and long-run estimates simultaneously. The study further applied Granger causality to find out the direction of causalities. To arrive at long-run robust estimates, the study used dynamic ordinary least squares (DOLS) model.

Findings

The results found that tourist receipts have no significant impact on environmental quality, while growth and energy consumption are the main determinants of CO2emissions in Pakistan. The Granger causality test confirmed unidirectional causalities from GDP and energy consumption toward CO2emissions, while tourist receipts do not affect environmental quality. DOLS technique confirmed the long-run estimates of ARDL model.

Research limitations/implications

The result of the study complements the literature by adding new evidence regarding the nexus of tourism and environment. Findings of the study are important for policymakers and regulatory bodies to place their focus on the development of tourism sector (services sector) rather than energy-intensive manufacturing activities to sustain the growth of the country in higher quartiles, as tourism receipts have no significant negative externalities toward environment, while energy use is one of the key determinants of environmental degradation.

Originality/value

This study used time series data over the period 1980-2016 for Pakistan to inspect the dynamic relationship between tourist receipts, economic growth, energy consumption and CO2emissions.
Short‐ and long‐term effects of maternal dyslipidaemia on blood pressure and baroreflex sensitivity in male rat offspring
Authors: de Araújo Emmanuel Veríssimo , Carneiro dos Santos Lucas Alves , Speretta Guilherme Fleury Fina , Ferreira Georgianna de Araújo Henriques , de Luna Freire Micaelle Oliveira , de Santana David Filipe , Carvalho‐Galvão Alynne , Cruz Josiane Campos , Costa-Silva João Henrique da , de Andrade Braga Valdir , de Brito Alves José Luiz
Published: September 2019

Maternal dyslipidaemia is a predisposing factor for arterial hypertension in male rat offspring at adulthood. This study was designed to investigate the short‐ and long‐term effects of maternal dyslipidaemia on blood pressure (BP) and baroreflex control in male rat offspring. Animals were obtained from mothers who received a dyslipidaemic (DLP, n = 7) or control (CTL, n = 7) diet during pregnancy and lactation. At 30 and 90 days of age, arterial pressure (AP), heart rate (HR) and baroreflex function were evaluated. In addition, spectral analysis of the systolic AP, diastolic AP, mean AP, HR, and spontaneous baroreflex were assessed. Data were expressed as mean ± SEM and Student's t‐test was used for comparison among groups, with statistical significance considered to be P < .05. At 30 days of age, male offspring had similar BP, HR and preserved baroreflex sensitivity. In addition, low frequency (LF) oscillation, high frequency (HF) oscillation and LF/HF ratio of AP and HR were similar in juvenile rats. At 90 days of age, male offspring from dyslipidaemic dams had augmented BP (P < .05) when compared to CTL group. Adult male rats from dyslipidaemic dams had a reduction in baroreflex control (P < .05) in comparison to CTL rats. The present study indicates that offspring from dams fed on a dyslipidaemic diet during pregnancy and lactation do not show alteration in blood pressure and baroreflex control in early life, but display a decline in baroreflex control and hypertension in adulthood.
The Review of the APS: Is gender really on anyone's agenda?
Authors: Colley Linda , Williamson Sue
Published: September 2019

As recently as 2016, the Australian Government stated its commitment to increasing gender equality in the Australian Public Service (APS) workforce. In May 2018, the Prime Minister announced a broad‐ranging Review of the APS, but gender equality was not mentioned in the Review Terms of Reference. An interim Review report was released in March 2019, which was also largely silent on gender issues. We examine the submissions to the Review to assess whether, and how, organisations have considered gender equality. We found an almost universal gender blindness in submissions and conclude that this may have contributed to the Review panel ignoring gender equality issues in their interim report. We further conclude that without a focus on gender equality within the Review and ensuing reforms, the APS gender equality strategy is rendered merely symbolic. We recommend the Review implement gender mainstreaming to ensure gender equality can progress in the APS.
Self‐segmenting of rennet‐induced milk gel in cheesemaking tank
Authors: Smykov Igor T
Published: September 2019

The phenomenon of self‐segmenting of milk gel in an open‐type cheesemaking tank is described. It is shown that the self‐segmenting of the gel is caused by the thermo‐gravitational convection of Rayleigh–Bénard and the thermo‐capillary convection of Bénard–Marangoni. A mechanism for the self‐segmenting of milk gel, in which the important role of fat globules in this process has been noted, is proposed. It is noted that the self‐segmenting of the milk gel can cause some defects in the finished cheese: uneven texture and colour disorder.
Randomised trial of population‐based BRCA testing in Ashkenazi Jews: long‐term outcomes
Authors: Manchanda R , Burnell M , Gaba F , Desai R , Wardle J , Gessler S , Side L , Sanderson S , Loggenberg K , Brady AF , Dorkins H , Wallis Y , Chapman C , Jacobs C , Legood R , Beller U , Tomlinson I , Menon U , Jacobs I
Published: September 2019

Objective

Unselected population‐based BRCA testing provides the opportunity to apply genomics on a population‐scale to maximise primary prevention for breast‐and‐ovarian cancer. We compare long‐term outcomes of population‐based and family‐history (FH)/clinical‐criteria‐based BRCA testing on psychological health and quality of life.

Design

Randomised controlled trial (RCT) (ISRCTN73338115) GCaPPS, with two‐arms: (i) population‐screening (PS); (ii) FH/clinical‐criteria‐based testing.

Setting

North London Ashkenazi‐Jewish (AJ) population.

Population/Sample

AJ women/men.

Methods

Population‐based RCT (1:1). Participants were recruited through self‐referral, following pre‐test genetic counselling from the North London AJ population.

Inclusion criteria: AJ women/men >18 years old; exclusion‐criteria: prior BRCA testing or first‐degree relatives of BRCA‐carriers.

Interventions: Genetic testing for three Jewish BRCA founder‐mutations: 185delAG (c.68_69delAG), 5382insC (c.5266dupC) and 6174delT (c.5946delT), for (i) all participants in PS arm; (ii) those fulfilling FH/clinical criteria in FH arm. Linear mixed models and appropriate contrast tests were used to analyse the impact of BRCA testing on psychological and quality‐of‐life outcomes over 3 years.

Main outcome measures

Validated questionnaires (HADS/MICRA/HAI/SF12) used to analyse psychological wellbeing/quality‐of‐life outcomes at baseline/1‐year/2‐year/3‐year follow up.

Results

In all, 1034 individuals (691 women, 343 men) were randomised to PS (n = 530) or FH (n = 504) arms. There was a statistically significant decrease in anxiety (P = 0.046) and total anxiety‐&‐depression scores (P = 0.0.012) in the PS arm compared with the FH arm over 3 years. No significant difference was observed between the FH and PS arms for depression, health‐anxiety, distress, uncertainty, quality‐of‐life or experience scores associated with BRCA testing. Contrast tests showed a decrease in anxiety (P = 0.018), health‐anxiety (P < 0.0005) and quality‐of‐life (P = 0.004) scores in both PS and FH groups over time. Eighteen of 30 (60%) BRCA carriers identified did not fulfil clinical criteria for BRCA testing. Total BRCA prevalence was 2.9% (95% CI 1.97–4.12%), BRCA1 prevalence was 1.55% (95% CI 0.89–2.5%) and BRCA2 prevalence was 1.35% (95% CI 0.74–2.26%).

Conclusion

Population‐based AJ BRCA testing does not adversely affect long‐term psychological wellbeing or quality‐of‐life, decreases anxiety and could identify up to 150% additional BRCA carriers.

Tweetable abstract

Population BRCA testing in Ashkenazi Jews reduces anxiety and does not adversely affect psychological health or quality of life.
Configurational demographic predictors of work–nonwork satisfaction
Authors: Farivar Farveh , Richardson Julia
Published: September 2019

Contemporary work–life balance research tends to treat demographic variables as moderators, grouping variables, or control variables influencing work and nonwork satisfaction. Yet earlier theories were premised on the assumption that they are, in fact, predictors of work and nonwork satisfaction even though those assumptions have not yet been tested empirically. Drawing on an Australian study comprising 798 white‐collar employees and using a fuzzy‐set qualitative comparative analysis technique, we investigate demographic variables as potential configurational predictors affecting work–nonwork satisfaction, defined as a combination of work satisfaction and nonwork satisfaction. The analysis revealed different scenarios and specific patterns between configurational solution terms leading to work–nonwork satisfaction. Employment status and age of children (specifically age differences between children) were the most important demographic variables influencing employees' work–nonwork satisfaction.
Consumers’ Impression of Minimally Processed Gala Apples Using Word Association
Authors: Krumreich F. D. , Seifert M. , Santos R. B. , Gularte M. A.
Published: September 2019

This study aimed to identify consumers’ preferences and impressions of minimally processed “Gala” cultivar apples, using preference tests and word associations. The study was conducted online via the Google Docs tool and sent out via social networks. The participants were 607 individuals, mostly women, mainly between the ages of 18 and 45, with education up to undergraduate and postgraduate level. As regards the preference for minimally processed apples, the profile of the consumer did not influence the choice. The profiles analyzed were gender and education. For the word association test, 11‐word categories were formed, and among these, the most important aspect was appearance, followed by taste and texture, which was confirmed by correspondence analysis. Sample A (0 days—no storage) was the most preferred one, differing significantly from the other samples, whereas sample B (3 days of storage) and sample C (6 days of storage) were associated with characteristics for choice of product. The word association methodology revealed the consumer's impressions of the product, in addition to demonstrating simplicity, low cost, speed, and an exploratory character.

Practical Application

Gender and level of schooling did not influence the choice of minimally processed apples. Appearance was the most cited word in the word association test. Word association is a simple, fast, inexpensive, and projective technique.
Effects of magnesium, phosphate and zinc supplementation in ICU patients—Protocol for a systematic review
Authors: Vesterlund Gitte Kingo , Thomsen Thordis , Møller Morten Hylander , Perner Anders
Published: September 2019

Background

Depletion of the trace elements magnesium, phosphate and zinc is common in patients admitted to the intensive care unit (ICU). Observational studies have suggested worse outcome in patients with hypomagnesaemia, hypophosphataemia or hypozincaemia, but also inverse associations with worse outcome with too high serum levels. However, it is unclear whether data from randomised clinical trials (RCTs) confirm this. Accordingly, we plan to assess the balance between benefits and harms of supplementation as compared with placebo or no supplementation in adult ICU patients.

Methods

We will conduct a systematic review of RCTs with meta‐analysis and trial sequential analysis in accordance with the Cochrane Handbook for Systematic Reviews of Interventions, the Preferred Reporting Items for Systematic Review and Meta‐Analysis (PRISMA) statement and the Grading of Recommendation, Assessment, Development and Evaluation (GRADE) approach. We will assess the effects of any supplementation with magnesium, phosphate or zinc vs. placebo or no treatment in adult ICU patients. We will systematically search the Cochrane CENTRAL, Embase, PubMed, and for unpublished trials: ClinicalTrials.gov, the EU clinical Trials Register and the WHO International Clinical Trials Registry Platform. The primary outcomes will be days alive without mechanical ventilation and overall mortality. Secondary outcomes include use for mechanical ventilation, tachy‐arrhythmias, use of vasopressors, length of hospital stay and use of renal replacement therapy.

Discussion

The benefits and harms of supplementation therapy with magnesium, phosphate and zinc in general ICU patients are unknown. This outlined systematic review will provide data on the evidence, on which future recommendations for supplementation may be founded.
Low‐ versus high‐dose intraoperative opioids: A systematic review with meta‐analyses and trial sequential analyses
Authors: Albrecht Eric , Grape Sina , Frauenknecht Jonathan , Kilchoer Laurent , Kirkham Kyle R.
Published: September 2019

Background

Opioid‐induced hyperalgesia is a state of nociceptive sensitisation secondary to opioid administration. The objective of this meta‐analysis was to test the hypothesis that high‐dose intraoperative opioids contribute to increased post‐operative pain and hyperalgesia when compared with a low‐dose regimen in patients under general anaesthesia.

Methods

We followed the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses statement guidelines and rated the certainty of evidence with the Grading of Recommendations, Assessment, Development and Evaluation system. Only trials investigating pain outcomes and comparing two different dosages of the same intraoperative opioid in patients under general anaesthesia were included. The primary outcome was pain score (analogue scale, 0‐10) at 24 post‐operative hours. Secondary outcomes included pain score and cumulative intravenous morphine equivalents (mg) consumed at 2 post‐operative hours, together with mechanical pain threshold (g·mm−2).

Results

Twenty‐seven randomised controlled trials, including 1630 patients, were identified. Pain score at rest at 24 post‐operative hours was increased in the high‐dose group (mean difference [95% CI]: −0.2 [−0.4, −0.1]; trial sequential analysis‐adjusted CI: −0.4, −0.02; low certainty of evidence). Similarly, at 2 post‐operative hours, both pain score (mean difference [95% CI]: −0.4 [−0.6, −0.2]; low certainty of evidence) and cumulative intravenous morphine equivalents consumed (mean difference [95% CI]: −1.6 mg [−2.6, −0.7]; low certainty of evidence) were significantly higher in the high‐dose group. Finally, the threshold for mechanical pain was significantly lower in the high‐dose group (mean difference to pressure [95% CI]: 3.8 g·mm−2 [1.8, 5.8]; low certainty of evidence).

Conclusions

There is low certainty of evidence that high‐dose intraoperative opioid administration increases pain scores in the post‐operative period, when compared with a low‐dose regimen.
Innate and Acquired Quinine‐Resistant Alcohol, but not Saccharin, Drinking in Crossed High–Alcohol‐Preferring Mice
Authors: Houck Christa A. , Carron Claire R. , Millie Lauren A. , Grahame Nicholas J.
Published: September 2019

Background

Alcohol consumption despite aversive consequences is often a key component of an alcoholism diagnosis. Free‐choice alcohol consumption despite bitter quinine adulteration in rodents has been seen following several months of free‐choice drinking, but there has been little study of whether prolonged access to other palatable substances such as saccharin yields quinine resistance. Selectively bred crossed high–alcohol‐preferring (cHAP) mice average blood alcohol levels of over 250 mg/dl during free‐choice access, considerably higher than other models. We hypothesized that higher intakes would yield more rapid development of quinine‐resistant alcohol (QRA) drinking and quinine‐resistant saccharin (QRS) drinking.

Methods

All experiments used male and female cHAP mice. Experiment 1 compared mice with either 0 or 5 weeks of alcohol drinking history, testing varying (0.032, 0.10, 0.32 g/l) quinine concentrations in ethanol. Experiment 2 examined whether innate QR may exist, comparing animals with a 1 or zero day of drinking history. Experiment 3 examined the effect of varying histories (0, 2, or 5 weeks) of free‐choice 10% alcohol drinking on QR alcohol consumption at high quinine concentrations. Finally, Experiment 4 investigated the development of QRS drinking.

Results

We found that we could not detect a history effect in commonly used quinine concentrations, indicating that cHAP mice are innately quinine resistant to 0.10 g/l quinine. However, we were able to determine that a 2‐week drinking history was sufficient to induce QRA drinking in cHAP mice at extremely high quinine concentrations (0.74 and 0.32 g/l). However, the history effect was specific to QRA, a saccharin drinking history, did not yield QRS drinking.

Conclusions

These data suggest that an alcohol drinking history induces maladaptive behaviors, such as drinking in spite of negative consequences, a pattern not seen with saccharin. Furthermore, a strong genetic predisposition to drink may promote an innate aversion resistance compared with commonly used inbred strains.
Histological and histochemical study of the proventriculus (Ventriculus glandularis) of common starling (Sturnus vulgaris)
Authors: Sayrafi Reza , Aghagolzadeh Mahboobeh
Published: September 2019

The histological and histochemical structures of the proventriculus of starling (Sturnus vulgaris) were examined using haematoxylin and eosin and special staining, that is periodic acid schiff (PAS), Masson's trichrome, Alcian blue, Orcein and Reticulin. All three cranial, middle and caudal parts of the proventriculus were also studied. The study results showed that the wall of the proventriculus consisted of mucosal, submucosal, muscular and serosal tunics. The mucosal tunic presented folds and sulci on its luminal surface. In the first third of the proventriculus, the tunica mucosa characterized by presence of folds lined by stratified squamous epithelium and presence of simple tubular glands in the lamina propria. In the middle and caudal thirds of the proventriculus, the surface was covered by a columnar epithelium, and the branched tubular glands were extended through the lamina propria. From the base of the branched tubular glands, the deep proventricular glands were observed that were compound tubuloalveolar lobules. The surface epithelium of the tunica mucosa and the cells lining the proventricular glands showed a positive reaction to PAS and Alcian blue stainings. In addition, the epithelial cells of the tubular and branched tubular glands showed Masson's trichrome‐positive reaction. The submucosal tunic was thin in the proventricular wall. The tunica muscularis was formed by a thin inner layer of longitudinal smooth muscle fibres and a thick outer layer of circular fibres. The serosa consisted of loose connective tissue, rich in blood vessels and covered by mesothelium.
Human sperm capacitation is necessary for SNARE assembly in neurotoxin‐resistant complexes
Authors: Mayorga L. , Altamirano K. , Zanni Ruiz E. , Pavarotti M.
Published: September 2019

Background

Capacitation is not a well‐defined process, required for the acrosome reaction triggered by physiological stimuli. In vitro, capacitation is achieved by sperm incubation in artificial media supplemented with HCO3−, Ca2+, and albumin. The role of capacitation in the membrane fusion machinery required for acrosomal exocytosis is not well‐known. SNARE proteins are fundamental for intracellular membrane fusion and acrosomal exocytosis. We have previously shown that in capacitated spermatozoa, the fusion machinery is maintained in an inactive state until the acrosome reaction is initiated. In particular, SNARE proteins are assembled in neurotoxin‐resistant complexes.

Objective

This work aimed to study the dynamic changes of SNARE complexes during capacitation.

Materials and Methods

The light chain of tetanus and botulinum neurotoxin has been widely used to study the configuration of SNARE proteins. For this purpose, we developed a recombinant light chain of tetanus neurotoxin linked to a polyarginine peptide. This membrane‐permeant protein was able to cleave cytosolic VAMP2 (a SNARE protein required for acrosome reaction) when present in a monomeric configuration.

Results

The results show that the VAMP2 is cleaved by the membrane‐permeant tetanus neurotoxin in non‐capacitated spermatozoa, indicating that, before capacitation, SNAREs are not assembled in stable toxin‐resistant complexes. However, 2 h of incubation in a capacitation medium containing albumin was sufficient to render VAMP2 insensitive to the toxin.

Discussion

We conclude that during capacitation, the SNARE proteins become engaged in stable fully assembled cis‐SNARE complexes. This step is likely essential to prevent untimely activation of the membrane fusion machinery.

Conclusion

We propose that capacitation promotes the stabilization of the membrane fusion machinery required for acrosomal exocytosis in preparation for the stimulus‐triggered acrosome reaction.
The relationship between systolic pulmonary arterial pressure and Tp‐e interval, Tp‐e/QT, and Tp‐e/QTc ratios in patients with newly diagnosed chronic obstructive pulmonary disease
Authors: Cosgun Ayhan , Oren Huseyin , Turkkani Mustafa Hamidullah
Published: September 2019

Introduction

The risk of sudden cardiac death (SCD) and arrhythmias has been shown to be common in chronic obstructive pulmonary disease (COPD) subjects. We aimed to evaluate the markers of arrhythmia such as QT, QTc (corrected QT), Tp‐e, and cTp‐e (corrected Tp‐e) intervals, Tp‐e/QT ratio, and Tp‐e/QTc ratio in newly diagnosed COPD subjects in both right and left precordial leads.

Materials and Methods

The study group consisted of 74 subjects with obstructive respiratory function tests (RFTs). The control group consisted of 78 subjects who had nonobstructive RFTs. RFTs, electrocardiograms (ECG), and transthoracic echocardiograms (TTE) were performed, and QTR (QT interval in right precordial leads), QTL (QT interval in left precordial leads), Tp‐eR (Tp‐e interval in right precordial leads), and Tp‐eL (Tp‐e interval in left precordial leads) intervals; systolic pulmonary arterial pressure (sPAP); forced expiratory volume in one second (FEV1)/forced vital capacity (FVC); and peripheral oxygen saturation(POS) values were measured.

Results

Tp‐eR interval 85.82 ± 5.34 millisecond (ms) versus 62.87 ± 3.55 ms (t = 31.29/p < .00001), cTp‐eR interval 97.51 ± 7.18 ms versus 71.07 ± 4.58 ms (t = 27.20/p < .00001), Tp‐eR/QTR ratio 0.234 ± 0.02 versus 0.164 ± 0.01 (t = 2.2/p = .014), and Tp‐eR/QTcR ratio 0.201 ± 0.01 versus 0.141 ± 0.01 (t = 1.92/p = .028) were statistically significantly higher in COPD subjects. There was a strong negative correlation between RFT and sPAP (sPAP, 29.93 ± 5.1 mm Hg; and FEV1/FVC, 63.78 ± 3.33%, r = −.85/p < .00001). There was a moderate positive correlation between sPAP and Tp‐eR.

Conclusion

We found Tp‐e and cTp‐e intervals, Tp‐e/QT ratio, and Tp‐e/QTc ratio were significantly higher in the COPD patients than in the control group. In addition, in the COPD group, heart rate variability (HRV) parameters were significantly lower on ECG.
Study of changes of obesity‐related inflammatory cytokines after laparoscopic sleeve gastrectomy
Authors: Salman Mohamed Abdalla , Salman Ahmed Abdallah , Nafea Mohammed A. , Sultan Ahmed Abd El Aal , Anwar Hisham W. , Ibrahim Ayman Helmy , Awad Abeer , Ahmed Reham Abdelghany , Seif El Nasr Sayed M. , Abouelregal Tarek Elsayed , Shaaban Hossam El‐Din , Mohamed Fatma Abdel Hamid
Published: September 2019

Background

Chronic inflammation in adipose tissue may play a substantial role in the pathogenesis of obesity‐related metabolic disorders. The present study aims to evaluate the changes in adipocytokines, bile acids, fibroblast growth factor 19 (FGF‐19) and pro‐inflammatory cytokines 6 months after laparoscopic sleeve gastrectomy (LSG).

Methods

This prospective study included 75 obese patients with body mass index >35 kg/m2 who underwent LSG. All patients were recruited preoperatively and followed up post‐operatively at 6 months, with laboratory assessment of their cytokines including adiponectin, leptin, resistin, bile acid, interleukin (IL)‐6, IL‐8, tumour necrosis factor‐α, monocyte chemotactic protein‐1, high‐sensitivity C‐reactive protein, plasminogen activator inhibitor‐1, serum amyloid‐A and FGF‐19.

Results

There were statistically highly significant changes regarding anthropometric parameters (weight, body mass index and waist‐to‐hip ratio), blood glucose and lipid profile as well as liver enzymes at 6 months post‐sleeve gastrectomy. The present study showed that the levels of serum adiponectin and FGF‐19 significantly increased at 6 months of follow‐up after surgery (P < 0.001), while the levels of serum leptin, resistin, high‐sensitivity C‐reactive protein, plasminogen activator inhibitor‐1 and serum amyloid‐A significantly decreased at 6 months of follow‐up after surgery (P < 0.001). There were no significant differences regarding serum bile acid, IL‐6, IL‐8, tumour necrosis factor‐α and monocyte chemotactic protein‐1.

Conclusion

Weight loss after LSG is associated with significant improvement of the adipokine levels towards anti‐diabetic and anti‐inflammatory profiles. Future studies should use a larger sample size and longer follow‐up periods.
Three times as much physical education reduced the risk of children being overweight or obese after 5 years
Authors: Kühr Petra , Lima Rodrigo Antunes , Grøntved Anders , Wedderkopp Niels , Klakk Heidi
Published: September 2019

Aim

We evaluated the effect that increasing physical education lessons from 1.5 to 4.5 hours per week for 5 years had on the body mass index (BMI) and waist circumferences of children aged 5‐11 years at inclusion.

Methods

From 2008 to 2013, six intervention schools in Svendborg, Denmark, delivered 4.5 hours of physical education lessons per week to 750 children. Meanwhile, four matched control schools gave 549 children the standard 1.5 hours of physical education lessons per week. Measurements were taken at baseline and yearly for 5 years. Of the 1299 children, 81 joined the schools after 2008.

Results

At baseline, the percentage of overweight children was 12% in the intervention schools and 13% in the control schools, whereas 15% and 19% were abdominal obese, respectively. After 5 years, the respective risks of remaining abdominal obese or overweight were 43% and 51% in the intervention schools and 78% and 84% in the control schools. Mean BMI increased 0.450 kg/m2 more in the control group over the five‐year period. The intervention was not effective in decreasing the average waist circumference.

Conclusion

Three times as much physical education lessons per week, for 5 years, effectively decreased BMI and the likelihood of remaining overweight or obese.
Bubbly and cystic appearance on chest radiograph of extremely preterm infants with bronchopulmonary dysplasia is associated with wheezing disorder
Authors: Arai Hirokazu , Ito Masato , Ito Tomoo , Ota Syozo , Takahashi Tsutomu ,   the Neonatal Research Network of Japan
Published: September 2019

Aim

Bubbly/cystic appearance on chest X‐ray (CXR) is an important factor in cases of severe bronchopulmonary dysplasia (BPD). We aimed to determine whether CXR ‐based BPD classifications obtained in extremely preterm infants with oxygen dependency at 28 days after birth (BPD28) is associated with wheezing disorders.

Methods

This was a multicentre retrospective cohort study of population data from infants (body weight, <1500 g) enrolled in the Neonatal Research Network of Japan. Of the 15 480 infants born at <28 weeks of gestation between 2003 and 2012, 8979 met the BPD28 criteria, and 4007 were classified as the no BPD28 group. BPD28 infants were classified according to the bubbly/cystic or no bubbly/cystic appearance on CXR at postnatal ≧28 days. The effects on wheezing disorder at 3 years of age were analysed.

Results

Bubbly/cystic BPD28 infants showed higher rates of wheezing disorders compared with no BPD28 infants. Bubbly/cystic BPD28 (odds ratio 1.7; 95% confidence interval, 1.3‐2.2) was a significant independent factor for wheezing disorders.

Conclusion

A bubbly/cystic appearance on CXR with BPD28 was a potential risk factor of wheezing disorders at 3 years of age. This may be a useful early diagnostic tool at ≧28 postnatal days in extremely preterm infants.