bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Different Antithrombotic Regimens on Platelet-Mediated Thrombin Generation in Patients with Left Ventricular Assist Devices
Authors: Consolo Filippo , Pozzi Loris , Pieri Marina , Della Valle Patrizia , Redaelli Alberto , D’Angelo Armando , Pappalardo Federico
Published: August 2019

We characterized the biologic background of prothrombotic platelet function in the setting of durable left ventricular assist devices (LVADs) evaluating the role of different antithrombotic regimens. Platelet-mediated thrombin generation was quantified using the Platelet Activity State (PAS) Assay and the Thrombin Generation Test (TGT) in 78 patients implanted with the HeartMate II (n = 10, 13%), the HeartMate 3 (HM3) (n = 30, 38%), or the HVAD (n = 38, 49%) and managed with oral anticoagulation plus aspirin (n = 46, 59%) or anticoagulation alone (n = 32, 41%). Coagulation parameters (platelet count, International Normalized Ratio (INR), activated Partial Thromboplastin Time, Fibrinogen and D-Dimer levels) and hemolysis (lactate dehydrogenase levels [LDH]) were also recorded to comprehensively characterize the hemostatic profile in the two groups. In patients without aspirin, the PAS assay revealed low-intensity increase in platelet prothrombinase activity (1.11-fold, p = 0.03). Similarly the TGT revealed moderate higher platelet reactivity when compared with patients receiving aspirin, consistent with reduction in lag time (0.87-fold, p < 0.001), increase in peak of thrombin generation (1.5-fold, p = 0.002) and thrombin generation rate (2-fold, p = 0.02), but comparable endogenous thrombin potential (p = 0.50). Coagulation parameters and LDH were comparable in the two groups (p > 0.05). Moreover, no differences were noted in platelet prothrombinase activity of patients implanted with the HM3 or HVAD. Our results suggest that, in the setting of durable LVADs, aspirin minimally modulates the biochemical pathway of platelet-mediated thrombin generation. Accordingly, re-evaluation of current antithrombotic management criteria in patients stratified according to bleeding/thromboembolic risk might be safe and beneficial to prevent adverse events.
Left Ventricular Assist Device Inflow Cannula Insertion Depth Influences Thrombosis Risk
Authors: Chivukula Venkat Keshav , Beckman Jennifer A. , Li Song , Masri S. Carolina , Levy Wayne C. , Lin Shin , Cheng Richard K. , Farris Stephen D. , Wood Gregory , Dardas Todd F. , Kirkpatrick James N. , Koomalsingh Kevin , Zimpfer Daniel , Mackensen G. Burkhard , Chassagne Fanette , Mahr Claudius , Aliseda Alberto
Published: August 2019

Left ventricular assist device (LVAD) use has continued to grow. Despite recent advances in technology, LVAD patients continue to suffer from devastating complications, including stroke and device thrombosis. Among several variables affecting thrombogenicity, we hypothesize that insertion depth of the inflow cannula into the left ventricle (LV) influences hemodynamics and thrombosis risk. Blood flow patterns were studied in a patient-derived computational model of the LV, mitral valve (MV), and LVAD inflow cannula using unsteady computational fluid dynamics (CFD). Hundreds of thousands of platelets were tracked individually, for two inflow cannula insertion depth configurations (12 mm—reduced and 27 mm—conventional) using platelet-level (Lagrangian) metrics to quantify thrombogenicity. Particularly in patients with small LV dimensions, the deeper inflow cannula insertion resulted in much higher platelet shear stress histories (SH), consistent with markedly abnormal intraventricular hemodynamics. A larger proportion of platelets in this deeper insertion configuration was found to linger in the domain for long residence times (RT) and also accumulated much higher SH. The reduced inflow depth configuration promoted LV washout and reduced platelet SH. The increase of both SH and RT in the LV demonstrates the impact of inflow cannula depth on platelet activation and increased stroke risk in these patients. Inflow cannula depth of insertion should be considered as an opportunity to optimize surgical planning of LVAD therapy.
Effect of positive end-expiratory pressure and positioning on jugular vein expansion in emergency department patients
Authors: Ehrlich Claudia , Hohenstein Christian , Winning Johannes , Rüddel Hendrik
Published: August 2019

Objective:

Guidelines recommend Trendelenburg position for central venous cannulation. Critically ill patients in the emergency department often do not tolerate this positioning or have contraindications. Thirty-degree dorsal elevated position with positive end-expiratory pressure by noninvasive ventilation could pose an alternative. This is the first trial to investigate the feasibility of alternative for central venous cannulation in critically ill emergency department patients.

Methods:

Ninety-one critically ill patients in the emergency department of Jena University Hospital were examined between August 2014 and May 2015. The cross-sectional area of the right internal jugular vein was measured in 3 different positions: 30° elevation, supine, and Trendelenburg position. Measurements were repeated with a continuous application of noninvasive ventilation.

Results:

Cross-sectional area of the right internal jugular vein in Trendelenburg position was largest (0.99 ± 0.66 cm2) compared to supine (0.57 ± 0.58 cm2) and 30° elevated position (0.25 ± 0.41 cm2). In 30° elevated positioning, application of positive end-expiratory pressure significantly enlarged cross-sectional area (0.62 ± 0.70 cm2). Noninvasive ventilation was a well-tolerated procedure (98%). In 30° elevated positioning with positive end-expiratory pressure a safe puncture (cross-sectional area ≥ 0.4 cm2) could be expected in 68.1% of cases.

Conclusion:

Thirty-degree elevated positioning with positive end-expiratory pressure via noninvasive ventilation could be a safe and well-tolerated alternative for central venous cannulation, especially for critically ill patients in emergency department unable to remain in Trendelenburg position. This proof-of-concept trial enables further studies with actual central venous cannulation.
Zero Harm During Transition in Care From the Emergency Department to Medical/Surgical Units
Authors: Loftin Edwin , Andrews Diane , Mikitarian George , LaManna Jacqueline
Published: August 2019

Background:

Health care–related errors are the third leading cause of death in the United States. When evidence-based processes are applied, harm related to health care errors can reach zero.

Purpose:

The purpose was to achieve zero preventable harm to patients during transitions in care from the emergency department (ED) to medical/surgical (Med/Surg) areas.

Methods:

A performance improvement process was used to drive the evidence-based design to eliminate harm in transitions from the ED to Med/Surg units. Once initial design was complete, small tests of change were deployed until zero harm was achieved.

Results:

Zero harm during transitions from the ED to Med/Surg areas was achieved. The use of formal performance improvement systems, tools, and evidence-based practices allows organizations to achieve and sustain zero harm during these transitions in care.

Conclusion:

This transitions project met multiple objectives. In addition, throughput efficiencies were realized.
Accuracy of Pulmonary Nodule Volumetry at Different Exposure Parameters in Low-Dose Computed Tomography: A Phantom Study
Authors: Liu Jieke , Qing Haomiao , Luo Hongbing , He Changjiu , Wang Chunhua , Ren Jing , Zhou Peng
Published: August 2019

Objective

To explore the exposure parameters with minimized radiation dose for accurate pulmonary nodule volumetry using low-dose computed tomography (LDCT).

Methods

An anthropomorphic chest phantom with 11 pulmonary nodules (6 solid nodules and 5 ground-glass opacities) was scanned using 256-slice multidetector computed tomography scanner at various tube voltage and current (combinations of 80, 100 and 120 kV with 10 to 30 mAs). Raw data sets were reconstructed using the hybrid iterative reconstruction method and nodule volume was calculated by a semiautomatic software. The absolute percentage error (APE) of nodule volume relating to the reference acquisition and contrast-to-noise ratio was measured.

Results

Nodule characteristic and tube voltage (P < 0.0001) as well as the interaction between nodule characteristic and tube voltage (P = 0.0026) contributed significantly to the mean difference of APE, while tube current did not (P = 0.21). Post hoc analysis revealed no significant difference was found between the APE at 100 kV and 120 kV in both solid nodules (2.3 ± 0.4% vs 1.8 ± 0.6%, P = 0.14) and ground-glass opacities (6.0 ± 0.5% vs 4.9 ± 0.6%, P = 0.11). Exploratory analyses further showed that the APE at 100 kV with 10 mAs did not differ from that at 120 kV with 30 mAs in both solid nodules (2.5 ± 0.5% vs 1.7 ± 0.3%, P = 0.025, corrected P = 0.20) and ground-glass opacities (6.4 ± 0.4% vs 4.8 ± 1.0%, P = 0.0084, corrected P = 0.068).

Conclusions

In our study, the exposure parameters with minimized radiation dose for accurate pulmonary nodule volumetry were found at 100 kV with 10 mAs, and the estimated effect radiation dose was as low as 0.2 mSv, suggesting the feasibility of further reducing radiation dose by decreasing tube voltage and current in LDCT lung screening.
Impact of Knowledge-Based Iterative Model Reconstruction on Image Quality and Hemodynamic Parameters in Dynamic Myocardial Computed Tomography Perfusion Using Low-Tube-Voltage Scan: A Feasibility Study
Authors: Tanabe Yuki , Kido Teruhito , Kurata Akira , Kouchi Takanori , Hosokawa Takaaki , Nishiyama Hikaru , Kawaguchi Naoto , Kido Tomoyuki , Uetani Teruyoshi , Mochizuki Teruhito
Published: August 2019

Objective

Knowledge-based iterative model reconstruction (IMR) yields diagnostically acceptable image quality in low-dose static computed tomography (CT). We aimed to evaluate the feasibility of IMR in dynamic myocardial computed tomography perfusion (CTP).

Methods

We enrolled 24 patients who underwent stress dynamic CTP using a 256-slice CT. Images were reconstructed using filtered back projection (FBP), hybrid IR, and IMR. Image quality and hemodynamic parameters were compared among three algorithms.

Results

Qualitative image quality and contrast-to-noise ratio were significantly higher by IMR than by FBP or hybrid IR (visual score: 4.1 vs. 3.0 and 3.5; contrast-to-noise ratio: 12.4 vs. 6.6 and 8.4; P < 0.05). No significant difference was observed among algorithms in CTP-derived myocardial blood flow (1.68 vs. 1.73 and 1.70 mL/g/min).

Conclusions

The use of knowledge-based iterative model reconstruction improves image quality without altering hemodynamic parameters in low-dose dynamic CTP, compared with FBP or hybrid IR.
Spotlight on the Association of Radioactive Iodine Treatment With Cancer Mortality in Patients With Hyperthyroidism is Keeping the Highest Risk From Antithyroid Drugs in the Blind Spot
Authors: Tulchinsky Mark , Brill A. Bertrand
Published: August 2019

July 1, 2019, JAMA Internal Medicine released online an article authored by Kitahara et al entitled “Association of radioactive iodine treatment with cancer mortality in patients with hyperthyroidism.” The Altmetric Attention Score, a global indicator of interest from lay public and colleagues, skyrocketed to 223 by July 7, placing the article in the top 5% of all scored reports. The overall perception of death from cancer risk associated with 131I is inflated and not supported by evidence. As co-authors of this article, we offer previously unpublished data and analysis that (1) disputes clinical significance of the associated risk from 131I and (2) shows, again, that antithyroid drugs carry a statistically significant and a much more obvious cancer death risk.
Laparoscopic Pancreaticodudenectomy for Periampullary Tumor: Should it be a Routine? A Propensity Score–matched Study
Authors: El Nakeeb Ayman , Attia Mohamed , El Sorogy Mohamed , Ezzat Helmy , Shehta Ahmed , Salem Aly , El Gawad Mohamed A. , Hamed Hosam , Allah Talaat A. , El-Geidi Ahmed A. , Fathy Omar , El Hefnawy Emad , Zaghloul Amgad
Published: August 2019

Introduction:

Laparoscopic pancreaticoduodenectomy (LPD) is a complex and challenging procedure even with experienced surgeons. The aim of this study is to evaluate the feasibility and surgical and oncological outcomes of LPD compared with open pancreaticoduodenectomy (OPD).

Patients and Method:

This is a propensity score–matched analysis for patients with periampullary tumors who underwent PD. Patients underwent LPD and matched group underwent OPD included in the study. The primary outcome measure was the rate of total postoperative morbidities. Secondary outcomes included operative times, hospital stay, wound length and cosmosis, oncological outcomes, recurrence rate, and survival rate.

Results:

A total of 111 patients were included in the study (37 LPD and 74 OPD). The conversion rate from LPD to OPD was 4 cases (10.8%). LPD provides significantly shorter hospital stay (7 vs. 10 d; P=0.004), less blood loss (250 vs. 450 mL, P=0.001), less postoperative pain, early oral intake, and better cosmosis. The length of the wound is significantly shorter in LPD. The operative time needed for dissection and reconstruction was significantly longer in LPD group (420 vs. 300 min; P=0.0001). Both groups were comparable as regards lymph node retrieved (15 vs. 14; P=0.21) and R0 rate (86.5% vs. 83.8%; P=0.6). No significant difference was seen as regards postoperative morbidities, re-exploration, readmission, recurrence, and survival rate.

Conclusions:

LPD is a feasible procedure; it provided a shorter hospital stay, less blood loss, earlier oral intake, and better cosmosis than OPD. It had the same postoperative complications and oncological outcomes as OPD.
Genetic affinities of an eradicated European Plasmodium falciparum strain
Authors: de-Dios Toni , van Dorp Lucy , Gelabert Pere , Carøe Christian , Sandoval-Velasco Marcela , Fregel Rosa , Escosa Raül , Aranda Carles , Huijben Silvie , Balloux François , Gilbert M. Thomas P. , Lalueza-Fox Carles
Published: August 2019

Malaria was present in most of Europe until the second half of the 20th century, when it was eradicated through a combination of increased surveillance and mosquito control strategies, together with cross-border and political collaboration. Despite the severe burden of malaria on human populations, it remains contentious how the disease arrived and spread in Europe. Here, we report a partial Plasmodium falciparum nuclear genome derived from a set of antique medical slides stained with the blood of malaria-infected patients from Spain’s Ebro Delta, dating to the 1940s. Our analyses of the genome of this now eradicated European P. falciparum strain confirms stronger phylogeographical affinity to present-day strains in circulation in central south Asia, rather than to those in Africa. This points to a longitudinal, rather than a latitudinal, spread of malaria into Europe. In addition, this genome displays two derived alleles in the pfmrp1 gene that have been associated with drug resistance. Whilst this could represent standing variation in the ancestral P. falciparum population, these mutations may also have arisen due to the selective pressure of quinine treatment, which was an anti-malarial drug already in use by the time the sample we sequenced was mounted on a slide.
GenomeScope 2.0 and Smudgeplots: Reference-free profiling of polyploid genomes
Authors: Ranallo-Benavidez T. Rhyker , Jaron Kamil S. , Schatz Michael C.
Published: August 2019

An important assessment prior to genome assembly and related analyses is genome profiling, where the k-mer frequencies within raw sequencing reads are analyzed to estimate major genome characteristics such as genome size, heterozygosity, and repetitiveness. Here we introduce GenomeScope 2.0 (https://github.com/tbenavi1/genomescope2.0), which applies combinatorial theory to establish a detailed mathematical model of how k-mer frequencies are distributed in heterozygous and polyploid genomes. We describe and evaluate a practical implementation of the polyploid-aware mixture model that, within seconds, accurately infers genome properties across thousands of simulated and eleven real datasets spanning a broad range of complexity. We also present a new method called Smudgeplots (https://github.com/KamilSJaron/smudgeplot) to visualize and infer the ploidy and genome structure of a genome by analyzing heterozygous k-mer pairs. We successfully apply the approach to systems of known variable ploidy levels in theMeloidogynegenus and also the extreme case of octoploidFragaria x ananassa.
A time-resolved imaging-based CRISPRi screening method
Authors: Camsund Daniel , Lawson Michael J. , Larsson Jimmy , Jones Daniel , Zikrin Spartak , Fange David , Elf Johan
Published: August 2019

Our ability to connect genotypic variation to biologically important phenotypes has been seriously limited by the gap between live cell microscopy and library-scale genomic engineering. Specifically, this has restricted studies of intracellular dynamics to one strain at a time and thus, generally, to the impact of genes with known function. Here we show howin situgenotyping of a library ofE. colistrains after time-lapse imaging in a microfluidic device overcomes this problem. We determine how 235 different CRISPR interference (CRISPRi) knockdowns impact the coordination of the replication and division cycles ofE. coliby monitoring the location of replication forks throughout on average >500 cell cycles per knockdown. The single-cell time-resolved assay allows us to determine the distribution of single-cell growth rates, cell division sizes, and replication initiation volumes. Subsequentin situgenotyping allows us to map each phenotype distribution to a specific genetic perturbation in order to determine which genes are important for cell cycle control. The technology presented in this study enables genome-scale screens of virtually all live-cell microscopy assays and, therefore, constitutes a qualitatively new approach to cellular biophysics.
Stromal Hedgehog pathway activation by IHH suppresses lung adenocarcinoma growth and metastasis by limiting reactive oxygen species
Authors: Kasiri Sahba , Chen Baozhi , Wilson Alexandra N. , Reczek Annika , Mazambani Simbarashe , Gadhvi Jashkaran , Noel Evan , Marriam Ummay , Mino Barbara , Lu Wei , Girard Luc , Solis Luisa M. , Luby-Phelps Katherine , Bishop Justin , Kim Jung-Whan , Kim James
Published: August 2019

Activation of the Hedgehog (Hh) signaling pathway by mutations within its components drives the growth of several cancers. However, the role of Hh pathway activation in lung cancers has been controversial. We demonstrate that the Hh signaling pathway is activated in lung stroma in a paracrine manner. Genetic deletion ofShhin autochthonous murine lung adenocarcinoma had no effect on survival. Early abrogation of the pathway by an anti-SHH/IHH antibody 5E1 led to significantly worse survival with increased tumor and metastatic burden. Loss of IHH byin vivoCRISPR led to more aggressive tumor growth suggesting that IHH, not SHH, activates the pathway in stroma to drive its tumor suppressive effects - a novel role for IHH in the lung. Tumors from mice treated with 5E1 had decreased blood vessel density and increased reactive oxygen species (ROS). Treatment of KP mice with 5E1 and N-acetylcysteine, as a ROS scavenger, decreased tumor ROS levels, inhibited tumor growth and prolonged mouse survival suggesting that increased ROS levels from stromal Hh pathway inhibition spurred lung tumor growth. Thus, IHH induces stromal Hh pathway activation to suppress tumor growth and metastases, in part, by limiting ROS production.
Structure of the native supercoiled flagellar hook as a universal joint
Authors: Kato Takayuki , Makino Fumiaki , Miyata Tomoko , Horváth Peter , Namba Keiichi
Published: August 2019

Bacteria swim in viscous liquid environments by using the flagellum1–3. The flagellum is composed of about 30 different proteins and can be roughly divided into three parts: the basal body, the hook and the filament. The basal body acts as a rotary motor powered by ion motive force across the cytoplasmic membrane as well as a protein export apparatus to construct the axial structure of the flagellum. The filament is as a helical propeller, and it is a supercoiled form of a helical tubular assembly consisting of a few tens of thousands of flagellin molecules4. The hook is a relatively short axial segment working as a universal joint connecting the basal body and the filament for smooth transmission of motor torque to the filament5,6. The structure of hook has been studied by combining X-ray crystal structure of a core fragment of hook protein FlgE and electron cryomicroscopy (cryoEM) helical image analysis of the polyhook in the straight form and has given a deep insight into the universal joint mechanism7. However, the supercoiled structure of the hook was an approximate model based on the atomic model of the straight hook without its inner core domain7and EM observations of supercoiled polyhook by freeze-dry and Pt/Pd shadow cast8. Here we report the native supercoiled hook structure at 3.1 Å resolution by cryoEM single particle image analysis of the polyhook. The atomic model built on the three-dimensional (3D) density map show the actual changes in subunit conformation and intersubunit interactions upon compression and extension of the 11 protofilaments that occur during their smoke ring-like rotation and allow the hook to function as a dynamic molecular universal joint with high bending flexibility and twisting rigidity.
Data-driven decision making in graduate students’ research topic selection
Authors: Li Qiao , Wang Ping , Sun Yifan , Zhang Yinglong , Chen Chuanfu
Published: August 2019

Purpose

With the advent of the intelligent environment, as novice researchers, graduate students face digital challenges in their research topic selection (RTS). The purpose of this paper is to explore their cognitive processes during data-driven decision making (DDDM) in RTS, thus developing technical and instructional strategies to facilitate their research tasks.

Design/methodology/approach

This study developes a theoretical model that considers data-driven RTS as a second-order factor comprising both rational and experiential modes. Additionally, data literacy and visual data presentation were proposed as an antecedent and a consequence of data-driven RTS, respectively. The proposed model was examined by employing structural equation modeling based on a sample of 931 graduate students.

Findings

The results indicate that data-driven RTS is a second-order factor that positively affects the level of support of visual data presentation and that data literacy has a positive impact on DDDM in RTS. Furthermore, data literacy indirectly affects the level of support of visual data presentation.

Practical implications

These findings provide support for developers of knowledge discovery systems, data scientists, universities and libraries on the optimization of data visualization and data literacy instruction that conform to students’ cognitive styles to inform RTS.

Originality/value

This paper reveals the cognitive mechanisms underlying the effects of data literacy and data-driven RTS under rational and experiential modes on the level of support of the tabular or graphical presentations. It provides insights into the match between the visualization formats and cognitive modes.
Population ageing and a lack of semi-skilled workers in Switzerland
Authors: Saner Raymond , Yiu Lichia , Rush Laurel
Published: August 2019

Purpose

The question being discussed in this paper is how can refugees be integrated into a host country’s labour market with Switzerland serving as a case example experiencing specific local challenges, such as an aging society and gaps in the labour market, particularly relating to semi-skilled jobs in the public sector. The paper aims to discuss this issue.

Design/methodology/approach

This paper examines Switzerland’s intake of refugees and analyses existing refugee and labour market policies and how the integration process is being managed by the authorities and responded to by Swiss citizens.

Findings

The analysis shows that refugees can potentially find jobs in all three segments of the Swiss labour market (highly skilled, semi-skilled and low-skilled labour) and provide mutually beneficial solutions for all parties concerned that include: for refugees seeking employment and asylum; for the aging population requiring care delivered by low- and semi-skilled workforce; and for public and private sector enterprises in need of qualified and motivated labour force.

Originality/value

This paper examines the interplay between refugees seeking work and demonstrates the importance of relating job entry by refuges with actual labour market constraints and opportunities of the host country, Switzerland.
Dual board governance structure and multi-bank performance: a comparative analysis between Islamic banks in Southeast Asia and GCC countries
Authors: Nomran Naji Mansour , Haron Razali
Published: August 2019

Purpose

This paper aims to examine the effect of dual board governance structure, i.e. Shari’ah supervisory board (SSB) and board of directors (BoD), on the performance of Islamic banks (IBs) in Southeast Asia region versus banks in the Gulf Cooperation Council (GCC) region.

Design/methodology/approach

This study uses a sample of 45 IBs over seven countries covering the period of 2007-2015 based on the GMM estimator – First Difference (2-step).

Findings

The findings reveal that SSB and BoD for IBs in both regions are segmented in terms of ROA (negative interaction) and integrated in terms of Zakat ratio (Zakat on equity [ZOE]) (positive interaction) only for Southeast Asia region. Furthermore, SSBs positively affect multi-bank performance in Southeast Asia while its effect is absent for GCC. This suggests that Shari’ah governance practices for IBs in Southeast Asia are stronger compared to GCC IBs. Finally, BoD has a significant association with low ZOE for IBs in both the regions.

Research limitations/implications

The implications of this research is that the unique agency theory depicted in this study can be inferred when analyzing how dual board structure affects IBs' performance.

Practical implications

For regulators in both regions, SSBs must be given real power to monitor BoD. They should also balance the number of SSB scholars with experience in Shari’ah, as well as in law, accounting and finance. It is also important that such a balance of scholars with PhD in these areas be required for Southeast Asia IBs. For the GCC’s regulators, CG practices need to be improved by giving due importance to SSB characteristics and BoD structure.

Originality/value

Though the effects of dual board structure on IBs' performance has been previously examined in the literature, only SSB size has been used as a single proxy of SSB governance. Furthermore, no empirical evidence is recorded to date on this issue in Southeast Asia and the GCC regions. One of the innovations of this paper is the use of multi-bank performance measures in the IBs performance and corporate governance.
Modelling and simulation of residual stress of strip during continuous annealing process
Authors: Su Chun-Jian , Li Yong , Yang De-Xing , Bai Zhen-Hua , Wang Rui , Lv Yu-Ting , Duan Jian-Gao
Published: August 2019

Purpose

The purpose of this study is to solve the key problem of the residual stress of strip in buckling and deviation during the continuous annealing process (CAP).

Design/methodology/approach

Considering the one-to-one correspondence between deformation and residual stress, the strip was divided into multiple elements. To obtain the total deformation of each element, the influence model of some factors on the deformation of steel strip element was established. Then, according to the constitutive equation of residual stress and deformation, and the deformation coordination relation between strip elements, a set of calculation model, which is suitable for residual stress of strip during CAP was established, the model precision was verified by finite element method simulation, and the influences on residual stress of strip were also analyzed.

Findings

The weighted calculation of comparison between analytical results and simulation shows that the accuracy of the analytical method is within 10 per cent, which fully meets the requirements.

Originality/value

The different residual stress of steel strip can be displayed quickly and intuitively in the synchronous process segment according to this model, which is of great importance to the prevention of strip buckling and deviation.
Vibration-damping characteristic analysis of constrained stand-off layer damping cylindrical shell using Rayleigh-Ritz method
Authors: Yan Bijuan , Liang Huijun , Jin Minjie , Li Zhanlong , Song Yong
Published: August 2019

Purpose

In the vibration reduction field, constrained stand-off layer damping cylindrical shell plays an important role. However, due to the lack of accurate analysis of its damping characteristics, this hinders its further research and application. Therefore, the purpose of this paper is concerned with an accurate solution for the vibration-damping characteristics of a constrained stand-off-layer damping cylindrical shell (CSDCS) under various classical boundary conditions and conducts a further analysis.

Design/methodology/approach

Based on the Rayleigh–Ritz method and the Hamilton principle, a dynamic model of CSDCS is established. Then the loss factor and the frequency of CSDCS are obtained. The correctness and convergence behavior of the present model are verified by comparing the calculation results with the literature. By using for various classical boundary conditions without any special modifications in the solution procedure, the characteristics of CSDCS with S-S, C-C, C-S, C-F and S-F boundaries are discussed.

Findings

The Rayleigh–Ritz method is effective in handling the problem of CSDCS with different boundaries and an accurate solution is obtained. The boundary conditions have an important influence on the vibration and damping behavior of the CSDCS.

Originality/value

Based on the Rayleigh–Ritz method and Hamilton principle, a dynamic model of CSDCS is established for the first time, and then the loss factor and frequency of CSDCS are obtained. In addition, the effectiveness of adding the stand-off layer between the base shell and the viscoelastic layer is confirmed by discussing the characteristics of CSDCS with S-S, C-C, C-S, C-F and S-F boundaries.
Exploring ethical consumption in different geographical places
Authors: Delistavrou Antonia , Katrandjiev Hristo , Sadeh Hamdi , Tilikidou Irene
Published: August 2019

Purpose

The purpose of this paper is to examine the three types of ethical consumption (positive, negative and discursive) simultaneously in three different geographical areas, namely, Hebron (PL), Sofia (BG) and Thessaloniki (GR).

Design/methodology/approach

Personal interviews were conducted in the three cities during autumn 2016 with the use of a structured questionnaire. Large enough samples were selected with the one-stage area sampling. The sampling unit was one adult person of all households in each randomly selected city block.

Findings

The consumers of all cities were not found frequently engaged in any ethical consumption type. Demographic analysis revealed extensive differences across each one of the behaviours in each one of the cities. Attitudinal and psychographic analyses indicated that consumers, who are less ethically disinterested and more generous, were found to be more frequently engaged in ethical purchase in all the three cities. Evidence was found that less ethically disinterested and more generous consumers are more likely to get engaged in boycotting calls, in Hebron and in Thessaloniki. Less ethically disinterested consumers were also found more active in discursive activities in Sofia and Thessaloniki.

Research limitations/implications

Certain amendments of the behavioural and attitudinal scales could be essential to ensure the same level of measurement accuracy in different geographical areas. Larger and more representative of the overall population samples are needed to facilitate the generalisation of the results. Examination of cultural and political perspectives might add to the understanding of consumers’ ethical consumption in different contexts.

Practical implications

Firms interested in adopting ethical strategies or consumer groups that would like to call a boycotting or a consumer activism campaign should address their communication strategies towards targets that are described by the results in regard to each geographical area.

Originality/value

This study added to the limited so far relevant knowledge about the simultaneous examination of the three types of the overall ethical consumption in three different cities; interesting differences and similarities were revealed.
Prices of short-stay accommodation: time series of a eurozone country
Authors: Gričar Sergej , Bojnec Štefan
Published: August 2019

Purpose

This paper aims to provide a reliable statistical model for time-series prices of short-stay accommodation and overnight stays in a eurozone country.

Design/methodology/approach

Exploiting the unit root feature, the cointegrated vector autoregressive model solves the problem of misspecification. Subsequently, variables are modelled for a long-run equilibrium with included deterministic variables.

Findings

The empirical results confirmed that overnight stays for foreign tourists were positively associated with the prices of short-stay accommodation.

Research limitations/implications

The major limitation lies in the data vector and its time horizon; its extension could provide a more specific view.

Practical implications

Findings can assist practitioners and hotel executives by providing the information and rationale for adopting seasonal volatility pricing. Structural breaks in price time-series have practical implications for setting seasonal-pricing schemes. Tourists could benefit either from greater price stability or from differentiated seasonal prices, which are important in the promotion of the price attractiveness of the tourist destination.

Originality/value

The originality of the paper lies in the applied unit root econometrics for tourism price time-series modelling and the prediction of short-stay accommodation prices.
Lesson Study: analytic stance and depth of noticing in post-lesson discussions
Authors: Karlsen Anne Mette Færøyvik , Helgevold Nina
Published: August 2019

Purpose

The purpose of this paper is to shed light on teachers’ attention to student learning in post-lesson discussions in Lesson Study (LS) by exploring the depth and analytic stance of noticing (van Es, 2011) and by identifying interactions that may extend or narrow the levels of noticing.

Design/methodology/approach

The study has dug deeply into post-lesson discussions in the context of two different LS groups at a Norwegian lower secondary school.

Findings

The paper provides empirical insights about crucial elements of teachers’ learning processes pertaining to their professional noticing. Sharing of rich descriptions of evidence of student learning appeared to be a necessary foundation for the deepening of the teacher groups’ analytic approach. The study highlights the importance of teacher groups’ openness and attention to the collected data and a shared willingness to go deep into the interpretations. Interthinking and exploratory talk (Littleton and Mercer, 2013) are emphasised as important social interaction and talk modes to deepen the analytic stance and depth of noticing.

Research limitations/implications

Even though this is a small study, it brings to light important knowledge about how interactions in post-research lesson discussions in LS can influence teachers’ professional noticing.

Practical implications

An implication of the study is to design observation forms that capture student learning as tools for teachers’ professional noticing.

Originality/value

This paper fulfils an identified need to investigate teachers’ learning processes in LS, including how interactions within a teacher group influence noticing.
A complexity perspective on logistics management
Authors: Nilsson Fredrik Ralf
Published: August 2019

Purpose

The purpose of this paper is to elaborate on how perspectives and assumptions embedded in the complexity paradigm contribute to make logistics management research better aligned with real-life logistics. This is necessary, due to increasing supply chain complexity caused by an increasing request for sustainable development (SD).

Design/methodology/approach

The research is exploratory and based on a narrative literature review of logistics and supply chain management (SCM) from a complexity science perspective. Qualitative research interviews have been conducted with 12 logistics and supply chain managers in international companies and have focussed on their daily experiences and the underlying assumptions related to their actual work.

Findings

Logistics and SCM research is embedded in the functionalistic paradigm with reductionistic assumptions as the dominant logic. These do not sufficiently align with the complexity related, for example, to the daily work of SD in logistics management practice.

Research limitations/implications

It is proposed that the inclusion of complexity-based assumptions in logistics management research can increase realism in the advancement of the discipline. A key result is that the recognition of logistics as complex means inclusion of human and social aspects – which is apparent in any logistics process or phenomenon – in logistics knowledge creation processes.

Practical implications

Increased realism in logistics management research by addressing complexity, instead of merely reducing it, will provide logistics and supply chain managers with increased understanding and appropriate knowledge when they deal with emerging challenges such as SD.

Originality/value

Based on Boulding’s levels of complexity, this paper challenges the underlying assumptions of logistics management in research and practice, and provides reflective frameworks for advancing the discipline and aligning it to the complexity of contemporary challenges in logistics management.
Quits and ladders: does mobility improve outcomes?
Authors: Privalko Ivan
Published: August 2019

Purpose

The purpose of this paper is to compare internal and external job mobility (quits and promotions) as separate mechanisms for workers improving earnings and job fit.

Design/methodology/approach

The authors sample the core workforce from the British Household Panel Survey, estimating the effects of quits and promotions on two sets of outcomes. The first is subjective; satisfaction with work, pay and hours. The second is objective realities about the job; gross monthly pay and weekly working hours. The authors use linear fixed-effects estimation to control for individual heterogeneity.

Findings

Quits and promotions are distinctly different mechanisms for improving earnings and job fit. Quits improve measures of job fit (satisfaction with work, pay and hours) but have little effect on earnings. Internal promotions bring earnings growth but have little effect on job fit. The findings shed light what drives “voluntary” mobility; internal mobility may be driven by higher “reservation wages” and career progression, while external mobility may be driven by job matching and the need to find more appropriate work.

Social implications

Researchers should treat mobile labour markets with scepticism. The growth of “boundaryless careers” may closer resemble a release valve for poor working conditions in a varied market than a growth in new opportunities for earnings and career progression.

Originality/value

Studies of job mobility overwhelmingly focus on the effects quitting without explicitly comparing this mobility to promotions. This omission gives an incomplete picture of mobility. Bringing promotions back into the discussion, helps to understand why workers commit to internal careers and firm tenure. The paper shows that quits and promotions yield distinctly different outcomes for core workers, despite both mobility types being labelled “voluntary”. Thus, the authors show that inequality in earnings and working conditions is closely tied to access to the “life-chances” of mobility; those who are able to pursue promotion are rewarded objectively; those who quit for a new employer seek a better job fit.
Use of quality tools and techniques and their integration into ISO 9001
Authors: Castello Jordi , De Castro Rudi , Marimon Frederic
Published: August 2019

Purpose

The purpose of this paper is to focus on the use of quality management tools and techniques and their integration into the ISO 9001:2008 standard in a wind power (WP) sector supply chain (SC).

Design/methodology/approach

The research project was carried out in 119 WP sector SC companies (i.e. component suppliers, wind turbine assemblers and wind farm operation and maintenance services) using the questionnaire method. The companies selected employ quality management systems (QMSs) which conform to the ISO 9001:2008 standard.

Findings

The survey findings reveal that the degree to which quality tools and techniques are used in the WP companies can be characterised as “high”. The results show that internal audits, flowchart diagrams and cost of poor quality are the most-commonly applied tools and techniques, although they also indicate some areas for further improvement, for instance, when using advanced and complex quality techniques such as design of experiments, quality function deployment or business process management. In addition to this, the findings reveal that ISO 9001:2008 establishes a favourable environment for the use of quality tools and techniques.

Research limitations/implications

The study was based on the perceptions of quality managers, quality engineers and company managers (subjective data) and did not examine the reasons for either not implementing and/or the difficulties encountered while implementing quality tools and techniques.

Practical implications

The specific findings indicate that employing quality tools and techniques is useful for managers, not only when implementing a QMS, but also when suggesting recommendations for improvement.

Originality/value

A change of developing a framework integrating the main QT&T procedures into the main ISO 9001 processes.
A meta-analytic study on exploration and exploitation
Authors: Shi Xiaofeng , Su Lixun , Cui Annie Peng
Published: August 2019

Purpose

This study aims to fill three theoretical gaps in previous literature on exploration and exploitation: the relationship between exploration and exploitation is inconclusive; the influences of exploration and exploitation on firm performance are not consistent; and no empirical studies have integrated the antecedents of exploration and exploitation from the different research fields.

Design/methodology/approach

The study conducted a meta-analysis to quantitatively synthesize 143 studies with 257 independent samples to understand the relationship between exploration and exploitation and their consequences and antecedents.

Findings

The results show that exploration and exploitation are positively correlated with each other, and both of them can boost firm performance. Moreover, firm capabilities, firm size, firm age, competitive intensity, market orientation and entrepreneurial orientation positively influence exploration, and firm resources, firm capabilities, firm size, firm age, market orientation and entrepreneurial orientation positively influence exploitation. Competitive intensity negatively influences exploitation. Surprisingly, market turbulence does not significantly influence exploration or exploitation.

Originality/value

The results not only contribute to the theories by reconciling the inconsistent results but also provide insight for firms with guidance about under what conditions they should use what strategies.
Preserving the Civil Reserve Air Fleet: sustaining America’s emergency lifeline
Authors: Gourdin Kent N.
Published: August 2019

Purpose

The purpose of this paper is to examine an issue of critical importance to America’s national security. The Civil Reserve Air Fleet (CRAF) is a public/private partnership between US air carriers and the Department of Defense (DOD) for the provision of contingency airlift services to the military in times of national need. Formed in 1951, the CRAF has only been activated twice, but it has continued to be a source of emergency air transportation should the nation require resources beyond those available from the US Air Force. Sweeping changes occurring in global trade, commercial aviation, national defense policy and foreign relations suggest that changes will be needed to maintain the CRAF as a strategic defense transportation resource.

Design/methodology/approach

This paper examines the long-standing national policy of relying on commercial interests to provide contingency transportation to the DOD in wartime. The CRAF will be singled out for closer examination in light of environmental changes occurring in the airline industry, international trade and global threats to the nation. The purpose of this analysis is to then assess the partnership’s ability to remain relevant in an uncertain future.

Findings

First, commercial cargo aircraft are downsizing thereby becoming less useful to the DOD. Second, there is no new wide-body military airlifter on the horizon. Third, threats from hostile nations are becoming more indirect and subtle, requiring planners to think “outside the box” when assessing the need for strategic airlift over the next 20-50 years.

Originality/value

The CRAF has not fundamentally changed since its inception in 1951. The time has come to reexamine the partnership to ensure that it remains America’s emergency lifeline.
Are there any antecedents of top-down knowledge hiding in firms? Evidence from the United Arab Emirates
Authors: Butt Atif Saleem , Ahmad Ahmad Bayiz
Published: August 2019

Purpose

The purpose of this paper is to explore the antecedents of top-down knowledge hiding in buying and supplying firms.

Design/methodology/approach

This study uses a multiple case study methodology by considering four UAE-based firms and further employing 20 semi-structured interviews with managers of buying and supplying firms having a local and foreign nationality.

Findings

Based on the qualitative interviews, senior managers were found to be intentionally hiding knowledge from their managers based on five individual, three interpersonal and two firm-level reasons.

Research limitations/implications

This study has some limitations. First, the results of this study are not generalizable to a broader population. Second, this study explores behavioural patterns with respect to United Arab Emirates culture only.

Practical implications

Firms can use the findings of this study to understand what really motivates senior managers to intentionally hide knowledge from their subordinates. Also, this study provides some constructive guidelines to firms/senior management, which can discourage the culture of knowledge hiding in firms.

Originality/value

This study contributes to knowledge management literature by revealing multi-level and multi-faceted antecedents of top-down knowledge hiding in buying and supplying firms in the supply chain context.