bluuebunny/crossref_metadata_2025 huggingface dataset:
An improved modified FMEA model for prioritization of lean waste risk
Authors: Sutrisno Agung , Gunawan Indra , Vanany Iwan , Asjad Mohammad , Caesarendra Wahyu
Published: October 2018

Purpose

Proposing an improved model for evaluating criticality of non-value added (waste) in operation is necessary for realizing sustainable manufacturing practices. The purpose of this paper is concerning on improvement of the decision support model for evaluating risk criticality lean waste occurrence by considering the weight of modified FMEA indices and the influence of waste-worsening factors causing the escalation of waste risk magnitude.

Design/methodology/approach

Integration of entropy and Taguchi loss function into decision support model of modified FMEA is presented to rectify the limitation of previous risk reprioritization models in modified FMEA studies. The weight of the probability components and loss components are quantified using entropy. A case study from industry is used to test the applicability of the integration model in practical situation.

Findings

The proposed model enables to overcome the limitations of using subjective determination on the weight of modified FMEA indices. The inclusion of the waste-worsening factors and Taguchi loss functions enables the FMEA team to articulate the severity level of waste consequences appropriately over the use of ordinal scale in ranking the risk of lean waste in modified FMEA references.

Research limitations/implications

When appraising the risk of lean waste criticality, ignorance on weighting of FMEA indices may be inappropriate for an accurate risk-based decision-making. This paper provides insights to scholars and practitioners and others concerned with the lean operation to understand the significance of considering the impact of FMEA indices and waste-worsening factors in evaluating criticality of lean waste risks.

Practical implications

The method adopted is for quantifying the criticality of lean waste and inclusion of weighting of FMEA indices in modified FMEA provides insight and exemplar on tackling the risk of lean waste and determining the most critical waste affecting performability of company operations.

Originality/value

Integration of the entropy and Taguchi loss function for appraising the criticality of lean waste in modified FMEA is the first in the lean management discipline. These findings will be highly useful for professionals wishing to implement the lean waste reduction strategy.
Determinants of retail store network expansion via shop-in-shops
Authors: Picot-Coupey Karine , Viviani Jean-Laurent , Amadieu Paul
Published: October 2018

Purpose

Why do some retail networks operate shop-in-shops along with stand-alone units while others do not? Drawing on a resource-based and intellectual capital (IC) perspective as a broad theoretical lens, the purpose of this paper is to focus on retailer-run shop-in-shops and examine the determinants of their adoption.

Design/methodology/approach

To gain a comprehensive understanding of shop-in-shop adoption by retail branded networks, a research design mixing a quantitative study (n= 170) and a qualitative study (n= 19) was adopted to test nine hypotheses regarding these determinants of the adoption of retailer-run shop-in-shops and explore in greater depth the processes whereby they actually occur.

Findings

The main findings show that intangible resources are major determinants of the choice to operate shop-in-shops while tangible resources are minor determinants. The more robust results of the analysis lie in the positive effect of own-label merchandise range, premium pricing strategy, positioning based on symbols, retail concept fast renewal and high sector specialisation on the choice to operate a shop-in-shop. The effect of financial constraints on the decision to expand via shop-in-shops is limited.

Research limitations/implications

The authors emphasise the importance of marketing-related and company-related characteristics in differentiating the likelihood of retail networks to expand via shop-in-shops. These results lend support to the relevance of a resource-based and IC perspective in explaining the propensity of retailers to develop via shop-in-shops.

Practical implications

The decision to operate shop-in-shops should depend on the extent to which intangible resources – the most important being retail positioning grounded in symbols, an own-label merchandise range, and a high retail branded network reputation – can be valued and enhanced. Expanding a retail network via shop-in-shops does not appear to be a financially constrained expansion strategy: it must be considered as a relevant first best strategy when an independent and young retail company has intangible resources to value but limited tangible resources.

Originality/value

The study contributes to channel management and retailing research in four ways. First, it precisely delineates the specific characteristics of shop-in-shops. Second, it provides theoretical explanations – based on a resource and IC perspective – of determinants that influence the choice of shop-in-shops. Third, it empirically tests the influence of marketing-related and company-related characteristics when adopting shop-in-shops. Fourth, it provides insights into how adopting shop-in-shops. To the authors’ knowledge, the research is on the first to analyse theoretically and test the determinants for the choice of retailer-run shop-in-shops.
How guanxi networking matters in the relation between market orientation and innovation in Asian emerging economies – the case of Markor
Authors: Chung Henry F.L.
Published: October 2018

Purpose

Research focusing on the relation between market orientation and innovation in the Asian emerging economy is limited. The purpose of this study is to advance the extant literature by investigating the relations among market orientation, guanxi networking and innovation using the MARKOR scale.

Design/methodology/approach

The research conclusion is drawn based on the experience of 122 Asian emerging market firms operating in a wide variety of industrial sectors. This study explores whether the three MARKOR components (intelligence generation, dissemination and responsiveness) and their interaction with business and political guanxi have a significant effect on firms’ strategic innovation success. Innovation is measured following the practice of the OECD. In addition to the quantitative analyses, this study conducted qualitative interviews with executives of eight respondent firms, to further consolidate the subjects under investigation. The integration of both qualitative and quantitative data enriches the conclusions drawn from the study.

Findings

The findings of this study confirm that, when operating in an Asian emerging economy, both intelligence generation and responsiveness have a positive and direct impact on innovation. Though intelligence dissemination has no direct influence on innovation, its alignment with business and political guanxi still leads to a positive effect on innovation. The coalition of responsiveness and political guanxi, however, has a negative influence on innovation. The results of this study add new insights to the extant literature and provide implications for future research and marketing practices in Asian emerging economies.

Originality/value

The findings of this study confirm that, when operating in an Asian emerging economy, both intelligence generation and responsiveness have a positive and direct impact on innovation. Though intelligence dissemination has no direct influence on innovation, its alignment with business and political guanxi still leads to a positive effect on innovation. The coalition of responsiveness and political guanxi, however, has a negative influence on innovation. The results add new insights to the extant literature and provide implications for future research and marketing practices in Asian emerging economies.
A study of customers’ perception of Islamic banking in Oman
Authors: Belwal Rakesh , Al Maqbali Ahmed
Published: October 2018

Purpose

The concept of Islamic banking (IB) as a discipline and the introduction of the full-fledged Islamic banks and Islamic windows are relatively newer developments in the banking sector in Oman. This paper aims to assess customers’ perceptions of the Islamic banks and IB windows in Oman.

Design/methodology/approach

Following the interpretive paradigm and an exploratory research design, data collected through personal interviews with a group of 60 respondents in two of the prominent cities in Oman were analysed qualitatively.

Findings

The study found that customers in Oman had mixed feelings about the Islamic Banks. While some of them were not sure if the banks follow the Islamic principles, a majority of them had not opened an account with the Islamic banks or Islamic windows. The study revealed some vulnerabilities in the areas of their operations, marketing practices, staff knowledge of products and customer-dealings, as well as customers’ understanding of Islamic banks, their principles and practices.

Practical implications

As the advent of IB is relatively new to Oman, the insights gained by this study will have wider implications for the growth of IB locally. The outcomes of this study would appraise the officials and regulators of Islamic banks and Islamic windows with customers’ perception of IB. The elimination of the identified weaknesses would help them to improve the knowledge, quality and the marketing and promotion of products and services while competing with the conventional banks.

Originality/value

This study is a pioneering effort to know the status of IB and customers’ motivations in Oman towards IB.
Human resource executives and post-IPO firm growth
Authors: Belsito Carrie A. , Reutzel Christopher R. , Collins Jamie D.
Published: October 2018

Purpose

The purpose of this paper is to examine the relationship between human resource (HR) executive representation in top management and the growth of newly public firms. It draws upon research on strategic leadership, strategic HR management and Penrose’s theory of firm growth to consider the role of HRs executives in addressing demands placed upon top managers in the pursuit of firm growth. This study attempts to extend the focus of research on the influence of HR executives on organizational outcomes

Design/methodology/approach

In order to test study hypotheses, this study analyses data from a sample of US newly public firms that underwent initial public offerings (IPO) during the 2007 calendar year. Study data were analyzed using ordinary least squares regression in order to test study hypotheses.

Findings

This study provides general support for study hypotheses. First, HR executive presence in top management was found to be positively related to post-IPO firm growth. Second, upper echelon size and the number of firm employees were found to weaken the positive effect of HR executive presence in top management on post-IPO firm growth.

Research limitations/implications

As a consequence of study design, the results found in this study may be limited with respect to their external validity. Therefore, researchers and practitioners are encouraged to use caution before generalizing study findings to other contexts.

Practical implications

This study provides implications for top management team staffing and the pursuit of firm growth. Newly public firms appear to benefit in terms of firm growth by including HR executives in top management. The benefits of doing so appear to be reduced for newly public firms as the size of their upper echelons and number of employees increase.

Originality/value

This study extends research on the firm level consequences of HR executive presence in top management as well as research on factors which influence firm growth.
Analysis of crowd stampede risk mechanism
Authors: Kefan Xie , Song Yu , Liu Sishi , Liu Jia
Published: October 2018

Purpose

The purpose of this paper is to analyze the crowd stampede risk mechanism from the perspective of systems thinking.

Design/methodology/approach

Causal loop diagram is drawn to outline the non-linear interactions among complex factors across the whole system and dissect the contributory factors of crowd stampede accident. To systematically construct the theoretical framework and find fundamental solutions, co-word analysis with Citespace is used to get the critical data. An agent-based simulation using Pathfinder is conducted to develop a spatial model for the Shanghai Stampede Accident that happened in 2014.

Findings

The causal loop diagram is formed to not only illustrate the symptomatic solutions with a quick fix but also dissect the fundamental solutions through an underlying systemic analysis. The simulation shows that crowd stampede experiences an interactive process of accumulation, trigger, delay, break and diffusion of risk factors within the crowd system. A linkage effect among the multidimensional characters of individuals and the system accelerates the stampede risk deterioration. There exists delay of the result of effect from the deep-level measure.

Practical implications

A top-down approach is offered to policymakers for crowd stampede risk protocol design and synergic emergency control that may reduce the risk of the stampede.

Originality/value

In this study, SDFT paradigm is proposed as the critical solution for the crowd stampede accident. In addition, a chain effect of energy and a linkage effect within the crowd system is illustrated for in-depth understanding of crowd stampede risk.
An entrepreneurial process model from an institutional perspective
Authors: SU Yufeng , WU Nengquan , Zhou Xiang
Published: October 2018

Purpose

Entrepreneurial process strongly relies on context. The previous entrepreneurship research in developed countries over-emphasizes on its economic impact, but ignores its social impact, which leads to the slow development of entrepreneurship theories. Transitioning China provides entrepreneurs with a typical environment where opportunities and constraints coexist, which is a new research area in the field of entrepreneurship study.

Design/methodology/approach

Based on the grounded theory approach, this paper generalizes a local entrepreneurial process model from a multiple case study.

Findings

The paper states that the interaction among entrepreneurs, opportunities and institutional context is the core of the process. To be specific, entrepreneurial process includes an inner and an outer mechanism. The inner mechanism is based on the relations among institutional constraints, entrepreneurs and opportunities: nascent entrepreneurs, forced by institutional constraints to start a business, undergo a psychological process with entrepreneurial angst, reflective learning and effectuation and finally create business opportunities. The outer mechanism is grounded in the relations among new ventures, institutional evolution and opportunity development: new ventures facilitate institutional evolution through institutional entrepreneurship strategies, which in turn supports the ventures in the sustainable development of opportunities.

Originality/value

This study illuminates the social and institutional impact of entrepreneurial behavior, which is gradually fading and forgotten in modern society. The findings of the study enrich the research on entrepreneurial process, entrepreneurial cognition and institutional entrepreneurship and also provide implications for entrepreneurs.
Hyperbranched unsaturated polyester amide synthesized by two-step method
Authors: Zheng Hongjuan , Song Weiqiang
Published: October 2018

Purpose

Hyperbranched poly(ester-amide)s (HPEAs) have been synthesized from diethanolamine and maleic anhydride with ethylene glycol as a core monomer by using a two-step method, which are marked as Hupea polymers, and dehydration was carried out in xylene under reflux.

Design/methodology/approach

In comparison with Hupea polymers was synthesized by one-pot method, Hupea polymers synthesized by two-step method has different structure and rheological properties. The intermediate monomer and the resulting polymer are characterized by FTIR and NMR spectroscopies.

Findings

All of Mw, Mn and Mw/Mn of the hyperbranch polymers decrease with the core/monomer molar ratio increasing. The intrinsic viscosity ([η]) of the polymers decreases with Mw increasing in the investigated range of Mw and scales as [η]∼Mw-0.82, which implies that the molecular weight grew faster with core/monomer molar ratio decreasing than the volume in the investigated range of core/monomer molar ratio.

Research limitations/implications

The hydrodynamic radius was calculated by using Einstein’s equation and scales as Rh ∼ Mw0.061, and the lower exponent reveals the slow growth in the volume of Hupea molecule. In addition, the viscosity of Hupea polymer in concentrated aqueous solution is independent of shear rate and slightly dependent on molecular weight.

Practical implications

Hyperbranched poly(ester-amide)s (HPEAs) were synthesized by using a two-step method, which had different structure and rheological properties.

Originality/value

Hupea polymers show different features from Hupea polymers in structure and rheological properties, which revealed that the synthesis process of HPEA has effect on its performance.
Effect of powder characteristics on parts fabricated via binder jetting process
Authors: Miyanaji Hadi , Momenzadeh Niknam , Yang Li
Published: October 2018

Purpose

This study aims to experimentally investigate the effect of the powder material characteristics on the qualities of the binder jetting additive manufacturing parts both before and after post processing (sintering).

Design methodology/approach

Three different types of the 316L stainless steel powder feedstock with various mean particle sizes and size distributions were studied. The influence of the powder particle size distributions and pore sizes on the powder bed packing densities and on the dynamics of the binder droplet-powder bed interactions were characterized. In addition, the surface roughness and densities of these parts both in the green state and after sintering were studied.

Findings

The results revealed the significant role of the powder feedstock characteristics on the liquid binder/powder bed interaction and consequently on the dimensional accuracies of the green parts. It was observed that the parts printed with the smaller mean particle sizes resulted in better surface finish and higher final densities after sintering. Furthermore, the hardness of the sintered parts produced with smaller powder particles exhibited higher values compared to the parts fabricated with the larger particles. On the other hand, larger particle sizes are advantageous for various green part qualities including the dimensional accuracies, green part densities and surface roughness.

Originality/value

This study establishes more comprehensive correlations between the powder feedstock characteristics and various quality criteria of the printed binder jetting components in both green and sintered states. These correlation are of critical importance in choosing the optimal process parameters for a given material system.
Interface geometries in 3D multi-material prints by fused filament fabrication
Authors: Ribeiro Micaela , Sousa Carneiro Olga , Ferreira da Silva Alexandre
Published: October 2018

Purpose

An issue when printing multi-material objects is understanding how different materials will perform together, especially because interfaces between them are always created. This paper aims to address this interface from a mechanical perspective and evaluates how it should be designed for a better mechanical performance.

Design/methodology/approach

Different interface mechanisms were considered, namely, microscopic interfaces that are based on chemical bonding and were represented with a U-shape interface; a macroscopic interface characterized by a mechanical interlocking mechanism, represented by a T-shape interface; and a mesoscopic interface that sits between other interface systems and that was represented by a dovetail shape geometry. All these different interfaces were tested in two different material sets, namely, poly (lactic acid)–poly (lactic acid) and poly (lactic acid)–thermoplastic polyurethane material pairs. These two sets represent high- and low-compatibility materials sets, respectively.

Findings

The results showed, despite the materials’ compatibility level, multi-material objects will have a better mechanical performance through a macroscopic interface, as it is based on a mechanical interlocking system, of which performance cannot be achieved by a simple face-to-face interface even when considering the same material.

Originality/value

The paper investigates the importance of interface design in multi-material 3D prints by fused filament fabrication. Especially, for parts intended to be subjected to mechanical efforts, simple face-to-face interfaces are not sufficient and more robust and macroscopic-based interface geometries (based on mechanical interlocking systems) are advised. Moreover, such interfaces do not raise esthetic problems because of their working principle; the 3D printing technology can hide the interface geometries, if required.
The FaaS system using additive manufacturing for personalized production
Authors: Kang Hyoung Seok , Noh Sang Do , Son Ji Yeon , Kim Hyun , Park Jun Hee , Lee Ju Yeon
Published: October 2018

Purpose

In this paper, a three-dimensional (3D) printer-based manufacturing line and supporting system, which supports personalized/customized manufacturing for individual businesses or start-up companies, was studied to evaluate the practicality of using additive manufacturing for personalization/mass customization.

Design/methodology/approach

First, factory-as-a-service (FaaS) system, which provides factory as a service to customers, was proposed and designed to manufacture various products within a distributed manufacturing environment. This system includes 3D printer-based material extrusion processes, vapor machine/computer numerical control machines as post-processes and assembly and inspection processes with an automated material handling robot in the factory. Second, a virtualization module for the FaaS factory was developed using a simulation model interfaced with a cloud-based order and production-planning system and an internet-of-things-based control and monitoring system. This is part of the system for manufacturing operations, which is capable of dynamic scheduling in a distributed manufacturing environment. In addition, simulation-based virtual production was conducted to verify and evaluate the FaaS factory for the target production scenario. Main information of the simulation also has been identified and included in the virtualization module. Finally, the established system was applied in a sample production scenario to evaluate its practicality and efficiency.

Findings

Additive manufacturing is a reliable, feasible and applicable technology, and it can be a core element in smart manufacturing and the realization of personalization/mass customization.

Originality/value

Various studies on additive manufacturing have been conducted with regard to replacing the existing manufacturing methods or integrating with them, but these studies mostly focused on materials or types of additive manufacturing, with few advanced or applied studies on the establishment of a new manufacturing environment for personalization/mass customization.
Design of backstepping control with CNN-based compensator for active magnetic bearing system subjected to input voltage saturation
Authors: Pati Avadh , Negi Richa
Published: October 2018

Purpose

The stability and input voltage saturation is a common problem associated with an active magnetic bearing (AMB) system. The purpose of this paper is to design a control scheme that stabilizes the single degree of freedom AMB system and also tackle the problem of input voltage saturation in the AMB system.

Design/methodology/approach

The proposed control technique is a combination of two separate control schemes. First, the Backstepping control scheme is designed to stabilize and control the AMB system and then Chebyshev neural network (CNN)-based compensator is designed to tackle the input voltage saturation when the system control action is saturated.

Findings

The mathematical and simulation results are presented to validate the effectiveness of proposed methodology for single-degree freedom AMB system.

Originality/value

This paper introduces a CNN-based compensator with Backstepping control strategy to stabilize and tackle the problem of input voltage saturation in the 1-DOF AMB systems.
Performance evaluation in CNC turning of AA6063-T6 alloy using WASPAS approach
Authors: Sahoo Priyabrata , Satpathy Mantra Prasad , Singh Vishnu Kumar , Bandyopadhyay Asish
Published: October 2018

Purpose

Surface roughness and vibration during machining are inevitable which critically affect the product quality characteristics. This paper aims to suggest the implementation of a multi-objective optimization technique to obtain the favorable parametric conditions which lead to minimum tool vibration and surface roughness of 6063-T6 aluminum alloy in computer numerically controlled (CNC) turning.

Design/methodology/approach

The case study has been accomplished according to response surface methodology RSM’s Box–Behnken design (BBD) matrix using Titanium Nitride-coated Tungsten Carbide insert in a dry environment. As the experimental results are quite nonlinear, a second-order regression model has been developed for the responses (surface roughness and tool vibration) in terms of input cutting parameters (spindle speed, feed rate and depth of cut). The goodness of fit of the models has also been verified with analysis of variance (ANOVA) results.

Findings

The significance efficacy of input parameters on surface roughness and tool vibrations has been illustrated through multi-objective overlaid 3D surface plots and contour plots. Finally, parametric optimization has been performed to get the desired response values under the umbrella of weighted aggregate sum product assessment (WASPAS) method and verified confidently with confirmatory test results.

Originality/value

The results of this study reveals that hybrid RSM with WASPAS method can be readily applicable to optimize multi-response problems in the manufacturing field with higher confidence.
An improved integrated control modeling of a high-power density interleaved non-inverting buck-boost DC-DC converter
Authors: Karimi Mohsen , Pichan Mohammad , Abrishamifar Adib , Fazeli Mehdi
Published: October 2018

Purpose

This paper aims to propose a novel integrated control method (ICM) for high-power-density non-inverting interleaved buck-boost DC-DC converter. To achieve high power conversion by conventional single phase DC-DC converter, inductor value must be increased. This converter is not suitable for industrial and high-power applications as large inductor value will increase the inductor current ripple. Thus, two-phase non-inverting interleaved buck-boost DC-DC converter is proposed.

Design/methodology/approach

The proposed ICM approach is based on the theory of integrated dynamic modeling of continuous conduction mode (CCM), discontinuous conduction mode and synchronizing parallel operation mode. In addition, it involves the output voltage controller with inner current loop (inductor current controller) to make a fair balancing between two stages. To ensure fast transient performance, proposed digital ICM is implemented based on a TMS320F28335 digital signal microprocessor.

Findings

The results verify the effectiveness of the proposed ICM algorithm to achieve high voltage regulating (under 0.01 per cent), very low inductor current ripple (for boost is 1.96 per cent, for buck is 1.1) and fair input current balance between two stages (unbalancing current less than 0.5A).

Originality/value

The proposed new ICM design procedure is developed satisfactorily to ensure fast transient response even under high load variation and the solving R right-half-plane HP zeros of the CCM. In addition, the proposed method can equally divide the input current of stages and stable different parallel operation modes with large input voltage variations.
Is Standardized Precipitation Index (SPI) a Useful Indicator to Forecast Groundwater Droughts? — Insights from a Karst Aquifer
Authors: Uddameri V. , Singaraju S. , Hernandez E.A.
Published: October 2018

The study sought to understand the relationships between meteorological and groundwater droughts on water levels and spring discharges in Edwards Aquifer, Texas. Standardized Precipitation Index (SPI)‐styled Standardized Groundwater Index (SGI) was used to quantify groundwater droughts. SGI time series signal was delayed and damped, while SPI was volatile. SGI values correlated well with SPI values that were observed five to eight months ago. Dynamic regression models with lagged SPI terms and autoregressive integrated moving average errors indicated a statistically significant yet weak relationship between Lag‐1 SPI and SGI. The utility of SPI for groundwater drought forecasting was minimal in this aquifer. Nonseasonal and seasonal autoregressive terms played an important role in forecasting SGI and highlighted the need for long‐term, high‐resolution monitoring to properly characterize groundwater droughts. Spring flows exhibited stronger and quicker responses to meteorological droughts than changes in storage. In aquifers with spring discharges, groundwater monitoring programs must make efforts to inventory and monitor them. Groundwater drought contingency measures can be initiated using SPI but this indicator is perhaps inappropriate to remove groundwater drought restrictions.
Carrying a logger reduces escape flight speed in a passerine bird, but relative logger mass may be a misleading measure of this flight performance detriment
Authors: Tomotani Barbara M. , Bil Wender , van der Jeugd Henk P. , Pieters Remco P. M. , Muijres Florian T.
Published: October 2018

The recent boost in bird migration studies following the development of various tracking devices raised awareness of how detrimental attaching devices can be for animals. Such effects can occur during migration, but also immediately post‐release if the device impairs escape flight performance and, consequently, the bird's ability to evade predators.

In this study, we investigated the effect of carrying a device on the escape flight speed and aerodynamic force production in a migratory passerine. We recorded upward‐directed escape flights of 15 male blackcaps. Each individual was tested without a tag, and when equipped with three different leg‐loop dummy tags with masses representing around 3%, 5%, and 7% of their body mass. The experiment was designed such that all individuals passed through all treatments in a randomized order.

We found that two factors affected flight speed in roughly equal amounts: first, tagged escape flights had lower flight speeds compared to the control flights, irrespective of tag mass. Second, we found an effect of the total mass, that is, the sum of the masses of the individual bird and of the tag, with heavier birds being slower. In contrast, flight speed was not correlated with relative tag mass in percentage of body mass, the metric commonly used in ethical guidelines for tag attachment. Aerodynamic flight force production also depended on total mass, with heavier birds producing higher forces. But these flight forces did not differ between flights with or without a tag.

We conclude that, when tagging birds, it is misleading to choose heavy individuals for tagging in order to minimize the tag mass as a percentage of body mass. This is particularly relevant in species for which body mass is not necessarily related to size, like migratory birds that accumulate large fat reserves. The lower escape speed in “tagged” flights could not be explained by differences in net flight force production, because these did not differ between flights with and without a tag. This suggests that the tag also affected pre‐flight take‐off dynamics, possibly due to a leg harness‐induced reduction in leg push‐off performance.
Cold tolerance of the invasive larch casebearer and implications for invasion success
Authors: Ward Samuel F. , Venette Robert C. , Aukema Brian H.
Published: October 2018

Larch casebearer became established in North America in the late 1800s. Cold temperatures are considered a limiting factor for the insect's range, yet the cold hardiness of larch casebearer has never been quantified.

We investigated (i) larval survival after acute and prolonged exposure to subzero temperatures and (ii) supercooling points (i.e. temperatures causing the onset of freezing) of overwintering and active larvae from November 2015 to April 2017.

We developed models linking exposure temperatures to survival and evaluated them with larvae from field conditions. Historical minimum temperature data were used to estimate changes in survival across time at a site in northern Minnesota.

The cold tolerance of larch casebearer changed significantly with season: both lower lethal temperatures and supercooling points were lowest in mid‐winter and highest in spring and autumn. For example, 50% survival was estimated after acute exposure to a mean ± SE temperature of −28.9 ± 1.77 °C in October, −40.8 ± 0.77 °C in January and −27.8 ± 1.00 °C in April.

A model predicting survival using supercooling points provided conservative estimates of overwintering survival because it overestimated survival by approximately 4% and 8% in 2016 and 2017, respectively.

Analysis of climate data suggested that overwintering survival could have increased significantly over the previous half century.
Variance component estimators OPE, NOPE and AOPE in linear mixed effects models
Authors: Ghosh Subir , Guo Li , Peng Luyao
Published: October 2018

Optimum variance component estimation methods that yield uniformly minimum variance quadratic unbiased estimators for a full dataset are often difficult or impossible to implement. In this paper we propose an estimator which is near optimal under some distributional assumptions that can be made without specifying an exact functional form. This estimator has an exact closed form expression. An average optimum estimator, which can be used when optimum estimators exist for subsets of the data, is also proposed. Performance comparisons of the proposed estimators are made individually with other popular estimators using simulated data. A performance comparison of the average optimum estimator is made under four constraints on the variance components. A real dataset is analysed using the proposed estimators. The robustness properties of the proposed estimators, in comparison with the other estimators, including the method of moments, are also investigated, using data simulated from a skew normal distribution. The average optimum estimator is strongly robust and far superior for estimating one of the variance components, as demonstrated by making comparisons with other methods. These comparisons are based on bias, mean squared error, and mean absolute deviation. The average estimator is moderately robust in respect of the estimation of the other variance components.
Physicians' Interactions with Peers: Empathic Accuracy during Shift Handovers on Intensive‐Care Units
Authors: Klumb Petra L. , Wicki Chantal , Rauers Antje
Published: October 2018

Background

We investigated how accurately physicians judge colleagues' states during shift handovers on intensive‐care units, the role of physician characteristics, and how accuracy is related to handover partners' satisfaction.

Methods

Using mobile phones, we assessed momentary judgements during N = 272 shift handovers by 36 physicians of five Swiss clinics. Physicians rated their own and their partner's affective states. We calculated the covariation of the perceiver's judgements of the partner's affect with the partner's self‐reported affect and the perceiver's own self‐reported affect. We then examined the moderation of these covariations by physicians' roles and experience.

Results

Overall, resident physicians were moderately successful in taking their counterparts' perspective: Perceiver's ratings of partner's affect and the latter's self‐ratings were significantly related. Associations between perceivers' ratings of their own and their partner's affect were also evident. None of the effects varied as a function of physicians' roles. There was an unexpected effect of job experience; physicians with more experience were more likely to project their own affect into the rating of partner's affect. Physicians' accuracy in judging the partner's tense arousal was related to the partner's satisfaction with the social interaction. This effect may have been mainly driven by instances in which low tension was accurately judged, however.
Prevalence ofCYP2D6*4 1934G/A polymorphism in Western IndianHIVpatients
Authors: Singh HariOm , Lata Sonam , Gangakhedkar Raman R.
Published: October 2018

HepaticCYP2D6enzyme metabolizes antiretroviral drugs (ARVs) including nevirapine. Polymorphism inCYP2D6gene affects drug metabolism and displays distinctive phenotypes in the population. Hence, we investigated the prevalence ofCYP2D6*41934G/A polymorphism in a total of 165HIVpatients that include 34 with and 131 without hepatotoxicity and 160 unrelated healthy controls by thePCR‐RFLPmethod. The prevalence ofCYP2D6*41934AAgenotype was higher in totalHIVpatients as compared to healthy controls (1.81% vs 0.6%,OR = 2.86). Similarly,CYP2D6*41934AAgenotype was much more prevalent inHIVpatients without hepatotoxicity as compared to healthy controls (2.3% vs 0.6%,OR = 2.87). Likewise,CYP2D6*41934AAgenotype was predominant in advancedHIVdisease stage as compared to healthy controls (3.8% vs 0.6%,OR = 6.15).CYP2D6*41934GAgenotype was distributed higher inHIVpatients taking tobacco and nevirapine as compared to non‐users (23.3% vs 19.3%,OR = 1.21, 21.0% vs 16.7%,OR = 1.2). Likewise,CYP2D6*41934GAgenotype was overrepresented in patients with hepatotoxicity taking alcohol + nevirapine as compared to alcohol non‐users + nevirapine users (20.00% vs 16.67%,OR = 1.25). Thus, there was no significant difference in genotype or allele frequencies ofCYP2D6*41934G/A polymorphism between the patients with hepatotoxicity and those without or healthy controls.
Bartonella quintana, past, present, and future of the scourge of World War I
Authors: Ruiz Joaquim
Published: October 2018

During World War I, a mysterious new disease affected soldiers on both sides of battle field. The first reports described a relapsing fever of unknown origin with body lice being suggested as the vector. The outbreak affected >1 000 000 people, mostly soldiers fighting in front‐line trenches. Shortly afterward, the illness was known as Trench fever, of which the causal infectious agent is currently classified as Bartonella quintana.
Interstices of Care: Re‐Imagining the geographies of care
Authors: Hanrahan Kelsey B. , Smith Christine E.
Published: October 2018

In this introduction we argue that taking a topological approach to care can encourage us to understand both how caring relations and practices are produced and the forms they take as they shift and transform. We suggest that thinking topologically about the articles collected in this special section highlights how caring actions and practices ripple out into the world beyond immediate caring relationships and the immediate moment. Responding to a call within geographies of care to be thoroughly attuned to the placed‐ness of caring relations and to contribute work that theorises from places beyond the global north, the papers in this collection are situated in diverse geographical and cultural contexts, thoroughly contextualised in place and time and explore complicated relations that shape and challenge care. The geographies of care presented in this collection are a sampling of the diverse forms of care that are possible and, we argue, that by employing a topological approach to care, the possibility of what care can be and mean multiplies and expands.
Evaluation of the venous drainage pattern of the splenic flexure by preoperative three‐dimensional computed tomography
Authors: Arimoto Akira , Matsuda Takeru , Hasegawa Hiroshi , Yamashita Kimihiro , Nakamura Tetsu , Sumi Yasuo , Suzuki Satoshi , Kakeji Yoshihiro
Published: October 2018

Introduction

Anatomical evaluation of the splenic flexure vein is essential for complete mesocolic excision with central vascular ligation when treating patients with splenic flexure cancer. Although there have been several studies relating to the arterial branches of the splenic flexure, very limited data are available regarding the variation in venous anatomy in this region.

Methods

Sixty‐six patients with colorectal cancer who underwent preoperative 3‐D CT between April 2016 and April 2017 were included in this retrospective study. The pattern of the venous drainage of the splenic flexure and its association with the inferior border of the pancreas were evaluated.

Results

The inferior mesenteric vein flowed into the splenic vein in 32 patients (48.5%), into the superior mesenteric vein in 27 patients (40.9%), and into the confluence of splenic vein and superior mesenteric vein in 7 patients (10.6%). The splenic flexure vein joined the inferior mesenteric vein in 62 patients (93.9%), the splenic vein in 2 patients (3.0%), and the middle colic vein in 2 patients (3.0%). The splenic flexure vein flowed into the inferior mesenteric vein below the level of the inferior border of the pancreas in 58 patients (90.6%) and above it in 4 patients (6.3%).

Conclusion

Preoperative evaluation of the venous pattern of the splenic flexure on 3‐D CT is useful before complete mesocolic excision with central vascular ligation to avoid intraoperative bleeding during splenic flexure cancer surgery.
Significance of CCN2 expression in bovine preimplantation development
Authors: Akizawa Hiroki , Yanagawa Yojiro , Nagano Masashi , Bai Hanako , Takahashi Masashi , Kawahara Manabu
Published: October 2018

In mammalian preimplantation development, the first cell lineage segregation occurs during the blastocyst stage, when the inner cell mass and trophectoderm (TE) differentiate. Species‐specific analyses are essential to elucidate the molecular mechanisms that underlie this process, since they differ between various species. We previously showed that the reciprocal regulation of CCN2 and TEAD4 is required for proper TE differentiation in bovine blastocysts; however, the function of CCN2 during early embryogenesis has remained otherwise elusive. The present study assessed the spatiotemporal expression dynamics of CCN2 in bovine embryos, and evaluated how changes to CCN2 expression (using a CCN2 knockdown (KD) blastocyst model) regulate the expression of pluripotency‐related genes such as OCT4 and NANOG. The conducted quantitative PCR analysis revealed that CCN2 mRNA was expressed in bovine oocytes (at the metaphase stage of their second meiosis) and embryos. Similarly, immunostaining detected both cytoplasmic and nuclear CCN2 at all analyzed oocyte and embryonic stages. Finally, both OCT4 and NANOG expression levels were shown to be significantly reduced in CCN2 KD blastocysts. Together, these results demonstrate that bovine CCN2 exhibits unique expression patterns during preimplantation development, and is required for the proper expression of key regulatory genes in bovine blastocysts.
Mechanisms that drive bone pain across the lifespan
Authors: Mantyh Patrick W.
Published: October 2018

Disorders of the skeleton are frequently accompanied by bone pain and a decline in the functional status of the patient. Bone pain occurs following a variety of injuries and diseases including bone fracture, osteoarthritis, low back pain, orthopedic surgery, fibrous dysplasia, rare bone diseases, sickle cell disease and bone cancer. In the past 2 decades, significant progress has been made in understanding the unique population of sensory and sympathetic nerves that innervate bone and the mechanisms that drive bone pain. Following physical injury of bone, mechanotranducers expressed by sensory nerve fibres that innervate bone are activated and sensitized so that even normally non‐noxious loading or movement of bone is now being perceived as noxious. Injury of the bone also causes release of factors that; directly excite and sensitize sensory nerve fibres, upregulate proalgesic neurotransmitters, receptors and ion channels expressed by sensory neurons, induce ectopic sprouting of sensory and sympathetic nerve fibres resulting in a hyper‐innervation of bone, and central sensitization in the brain that amplifies pain. Many of these mechanisms appear to be involved in driving both nonmalignant and malignant bone pain. Results from human clinical trials suggest that mechanism‐based therapies that attenuate one type of bone pain are often effective in attenuating pain in other seemingly unrelated bone diseases. Understanding the specific mechanisms that drive bone pain in different diseases and developing mechanism‐based therapies to control this pain has the potential to fundamentally change the quality of life and functional status of patients suffering from bone pain.
Can women in labor give informed consent to epidural analgesia?
Authors: Wada Kyoko , Charland Louis C. , Bellingham Geoff
Published: October 2018

There are reasons to believe that decision‐making capacity (mental competence) of women in labor may be compromised in relation to giving informed consent to epidural analgesia. Not only severe labor pain, but also stress, anxiety, and premedication of analgesics such as opioids, may influence women’s decisional capacity. Decision‐making capacity is a complex construct involving cognitive and emotional components which cannot be reduced to ‘understanding’ alone. A systematic literature search identified a total of 20 empirical studies focused on women’s decision‐making about epidural analgesia for labor pain. Our review of these studies suggests that empirical evidence to date is insufficient to determine whether women undergoing labor are capable of consenting to epidural analgesia. Given such uncertainties, sufficient information about pain management should be provided as part of prenatal education and the consent process must be carefully conducted to enhance women’s autonomy. To fill in the significant gap in clinical knowledge about laboring women’s decision‐making capacity, well‐designed prospective and retrospective studies may be required.
Instrumental Variable Based Estimation Under the Semiparametric Accelerated Failure Time Model
Authors: Huling Jared D. , Yu Menggang , O'Malley A. James
Published: October 2018

Randomized controlled trials are the gold standard for estimating causal effects of treatments or interventions, but in many cases are too costly, too difficult, or even unethical to conduct. Hence, many pressing medical questions can only be investigated using observational studies. However, direct statistical modeling of observational data can result in biased estimates of treatment effects due to unmeasured confounding. In certain cases, instrumental variable based techniques can be used to remove such biases. These techniques are indeed widely studied and used in econometrics under parametric outcome models, however limited works have focused on the utilization of instrumental variables in survival analysis, where semiparametric models are often necessary. The additional challenge in analyzing survival data is the presence of censoring. In this paper, we introduce an instrumental variable method that relaxes the strong assumptions of previous works and provides consistent estimation of the causal effect of a treatment on a survival outcome. We demonstrate the efficacy of our method in various simulated settings and an analysis of Medicare enrollment data comparing two prevalent surgical procedures for abdominal aortic aneurysm from an observational study.