bluuebunny/crossref_metadata_2025 huggingface dataset:
Automated external defibrillator use and outcomes after out-of-hospital cardiac arrest: an Israeli cohort study
Authors: Merdler Ilan , Sadeh Ben , Hochstadt Aviram , Kofman Natalia , Szekely Yishay , Steinvil Arie , Shacham Yacov
Published: October 2019

Background

Out-of-hospital cardiac arrests (OHCA) are a serious healthcare situation with low survival rates. Application of an automated external defibrillator (AED) by bystanders shortens time to defibrillation and increases survival. In Israel, a regulation ensuring the presence of AED in public places was issued and implemented since 2014. We investigated whether this regulation had an impact on the outcomes of OHCA patients.

Methods

We performed a retrospective, single-center observational study. Included in the cohort were patients who were admitted to the department of intensive care cardiac unit with OHCA. Patients were stratified into two groups according to the year the regulation was introduced: group 1 (2009–2013) and group 2 (2014–2018).

Results

A total of 77 patients were included in group 1 and 61 in group 2. The utilization of AED was significantly higher in group 2 compared to group 1 (42% vs. 27%; P = 0.04). Compared to group 1 patients, group 2 had lower 48 h (0% vs. 8%; P = 0.02) and 30-day mortality (28% vs. 42%; P = 0.02). Cognitive damage following recovery was less frequent in group 2 (55% vs. 81%; P = 0.01).

Conclusion

Deployment of AEDs in public places by mandatory regulations increased utilization for OHCA and may improve outcomes.
CHA2DS2-Vasc score and saphenous vein graft disease in patients with coronary artery bypass graft surgery
Authors: Yarlioglues Mikail , Oksuz Fatih , Yalcinkaya Damla , Duran Mustafa , Murat Sani Namik
Published: October 2019

Background

Saphenous vein grafts (SVGs) are still frequently used in coronary artery bypass graft surgery (CABG). However, the patency rate of SVGs is lower than arterial grafts. CHA2DS2-VASc score gives important information about the prognosis of various cardiovascular diseases. In this study, we aimed to investigate the association between CHA2DS2-VASc score and saphenous vein graft disease (SVGD) in patients with history of CABG surgery.

Methods

A total of 241 patients who had undergone CABG surgery and who underwent coronary angiography due to stable angina pectoris symptoms were reviewed retrospectively. SVGD was defined as ≥50% stenosis in at least one SVG. Patients were divided into two groups according to the presence or absence of SVGD.

Results

It was found that CHA2DS2-VASc scores were significantly higher in SVGD group. In multivariate logistic regression analysis, time interval after CABG [odds ratio (OR) = 1.077, 95% confidence interval (CI) 1.004–1.155; P = 0.037], and CHA2DS2-VASc score ≥ 4 (OR = 10.10, 95% CI 4.739–21.276; P < 0.001) were found to be independent predictors of SVGD.

Conclusion

For the first time, our results have suggested that CHA2DS2-VASc score, which is commonly used in daily clinical practice and easy to calculate, can provide useful information for the risk assessment of patients with SVGs.
Diabetes mellitus is not independently associated with mortality in elderly patients with ST-segment elevation myocardial infarction. Insights from the Codi Infart registry
Authors: Gual Miquel , Ariza-Solé Albert , Formiga Francesc , Carrillo Xavier , Bañeras Jordi , Tizón Helena , Garcia-Picart Joan , Cárdenas Mérida , Regueiro Ander , Tomás Carlos , Rojas Sergio , Muñoz-Camacho Juan F. , Rosas Alba , Sánchez-Salado José C. , Lorente Victòria , Roura Gerard , Alegre Oriol , Gómez-Hospital Joan A. , Lidón Rosa M , Cequier Angel
Published: October 2019

Background

Diabetes mellitus predicts poorer outcomes in patients with acute coronary syndrome (ACS), but the magnitude of this association in patients at older ages remains controversial.

Methods

Data were extracted from the Codi Infart database. All consecutive patients with diagnosis of ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI) between 2010 and 2015 were included. We assessed the impact of diabetes mellitus on 30-day and one-year mortality in patients aged less than and at least 75 years.

Results

A total of 12 792 cases were registered, of whom 3023 (23.6%) were aged at least 75 years. About 20% patients had previous diabetes mellitus diagnosis. Patients aged at least 75 years had higher prevalence of comorbidities, higher proportion of heart failure at admission, a more extensive coronary artery disease and significant delay to reperfusion (P < 0.001). Diabetes mellitus was associated with higher 30-day mortality both in young [odds ratio (OR) 1.97, 95% confidence interval (CI): 1.43–2.70] and in elderly patients (OR 1.43, 95% CI: 1.07–1.91). After adjusting for potential confounders, this association remained significant in young patients (OR 1.47, 95% CI: 1.00–2.16, P = 0.047), but not in the elderly (OR 1.14, P = 0.43). Likewise, a crude association between diabetes mellitus and one-year mortality was observed in both groups (young patients: HR = 1.93; 95% CI: 1.51–2.46; older patients: HR = 1.33; 95% CI: 1.08–1.64). However, after adjusting for potential confounders, this association remained significant in younger patients (HR = 1.46; 95% CI: 1.13–1.89; P < 0.001), but not in the elderly (HR = 1.16; P = 0.17).

Conclusion

A significant proportion of these nonselected patients with STEMI had previous diabetes mellitus. The association between diabetes mellitus and outcomes is different according to age.
177Lu-DOTATATE peptide receptor radionuclide therapy versus Everolimus in advanced pancreatic neuroendocrine tumors: a systematic review and meta-analysis
Authors: Satapathy Swayamjeet , Mittal Bhagwant Rai
Published: October 2019

Objective

Advanced pancreatic neuroendocrine tumors (pNETs) present a therapeutic challenge with targeted therapies like Everolimus and 177Lu-DOTATATE peptide receptor radionuclide therapy (PRRT) showing beneficial effects in various cohort studies and randomized trials. Currently there is a paucity of trials with head-to-head comparison between PRRT and Everolimus in advanced pNETs. This systematic review was conducted to compare the therapeutic efficacy and safety profile of 177Lu-DOTATATE and Everolimus in advanced pNETs.

Methods

The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Searches in Pubmed, Scopus and Embase using relevant keywords selected articles up to June 2019. Data on efficacy and safety were extracted from the individual articles. Random effects model was used for meta-analysis.

Results

Fifteen articles consisting of 697 patients reported on 177Lu-DOTATATE and 12 articles consisting of 946 patients reported on Everolimus. Overall, treatment with 177Lu-DOTATATE had better objective response rate (47% vs. 12%, P < 0.001) and disease control rate (81% vs. 73%, P < 0.001) and longer progression-free survival (25.7 months vs. 14.7 months, P < 0.001) than with Everolimus. 177Lu-DOTATATE also had a better safety profile than Everolimus with fewer patients showing grade 3/4 hematological toxicity (5% vs. 11%, P = 0.02) and nephrotoxicity (1% vs. 2.5%, P = 0.34). Treatment-related adverse events caused discontinuation of therapy more frequently for Everolimus than for 177Lu-DOTATATE (59 out of 371 patients vs. 0 out of 128 patients).

Conclusion

From this meta-analysis, 177Lu-DOTATATE showed better therapeutic efficacy and safety profile compared to Everolimus in advanced pNETs.
Targeting ABL1 or ARG Tyrosine Kinases to Restrict HIV-1 Infection in Primary CD4+ T‐Cells or in Humanized NSG Mice
Authors: McCarthy Stephen D.S. , Leontyev Danila , Nicoletti Pauline , Binnington Beth , Kozlowski Hannah N. , Ostrowski Mario , Cochrane Alan , Branch Donald R. , Wong Raymond W.
Published: October 2019

Background:

Previous studies support dasatinib as a potent inhibitor of HIV-1 replication. However, a functional distinction between 2 kinase targets of the drug, ABL1 and ARG, has not been assessed.

Setting:

We used primary CD4+ T‐cells, CD8-depleted peripheral blood mononuclear cells (PBMCs) from a treatment naïve HIV-1+ patient, and a humanized mouse model of HIV-1 infection. We assessed the roles of ABL1 and ARG during HIV-1 infection and use of dasatinib as a potential antiviral against HIV-1 in humanized mice.

Methods:

Primary CD4+ T‐cells were administered siRNA targeting ABL1 or ARG, then infected with HIV-1 containing luciferase reporter viruses. Quantitative polymerase chain reaction of viral integration of 4 HIV-1 strains was also assessed. CD8-depleted PBMCs were treated for 3 weeks with dasatinib. NSG mice were engrafted with CD34+ pluripotent stem cells from human fetal cord blood, and infected with Ba-L virus after 19 weeks. Mice were treated daily with dasatinib starting 5 weeks after infection.

Results:

siRNA knockdown of ABL1 or ARG had no effect on viral reverse transcripts, but increased 2-LTR circles 2- to 4-fold and reduced viral integration 2- to 12-fold. siRNA knockdown of ARG increased SAMHD1 activation, whereas knockdown of either kinase reduced RNA polymerase II activation. Treating CD8-depleted PBMCs from a treatment-naïve patient with 50 nM of dasatinib for 3 weeks reduced p24 levels by 99.8%. Ba-L (R5)-infected mice injected daily with dasatinib showed a 95.1% reduction in plasma viral load after 2 weeks of treatment.

Conclusions:

We demonstrate a novel nuclear role for ABL1 and ARG in ex vivo infection experiments, and proof-of-principle use of dasatinib in a humanized mouse model of HIV-1 infection.
Use of Modeling and Simulations to Determine Raltegravir Dosing in Neonates: A Model for Safely and Efficiently Determining Appropriate Neonatal Dosing Regimens: IMPAACT P1110
Authors: Clarke Diana F. , Mirochnick Mark , Acosta Edward P. , Capparelli Edmund , Chain Anne , Teppler Hedy , Smith Betsy , Lommerse Jos ,   for the International Maternal Pediatric Adolescent AIDS Clinical Trials (IMPAACT) P1110 Study Team
Published: October 2019

Background:

Population modeling and simulations can be used to facilitate the conduct of phase I studies to develop safe and effective dosing regimens in neonates.

Setting:

P1110 is an international, multicenter trial to determine safe and effective raltegravir doses in neonates at risk for HIV infection.

Methods:

P1110 used a 2-cohort adaptive design incorporating population pharmacokinetic modeling and simulations. An initial cohort of neonates received 2 single oral doses of raltegravir with standard-of-care therapy for prevention of perinatal transmission—one within 48 hours of birth and a second at 7–10 days of life. Raltegravir concentration data after administration of these doses were combined with data from a previous study of infants aged 4 weeks to 2 years. The combined database was used for population pharmacokinetic modeling and simulations to select a daily dosing regimen for investigation in a second cohort of neonates.

Results:

Raltegravir concentration data from 6 neonates were combined with data from infants aged 4 weeks to 2 years receiving raltegravir twice daily. The combined data set allowed for successful development of a population pharmacokinetic model with reasonable precision of parameter estimates. Monte Carlo simulations were run to evaluate potential daily dosing regimens from birth to 6 weeks of age, allowing for selection of a regimen to be evaluated in a subsequent cohort of neonates receiving chronic raltegravir dosing.

Conclusions:

An adaptive design incorporating population pharmacokinetic modeling and simulations was used to select a developmentally appropriate neonatal raltegravir dosing regimen in the first 6 weeks of life.
“Namaste Flap”
Authors: Karki Durga , Muthukumar Vamseedharan , Dash Suvashis
Published: October 2019

Introduction

The reconstruction of the postburn contracture area is always a challenge in the field of plastic surgery. Moreover, the joints are very sensitive to trauma and immobilization, showing a susceptibility to stiffness. The aim of this article is to emphasize the use of “Namaste flap”—modification of subcutaneous pedicle propeller flaps in the reconstruction of postburn axillary and elbow contractures.

Methodology

This is a prospective case study of axillary and elbow contractures managed at a tertiary care hospital using Namaste flap—modification of subcutaneous pedicle propeller flaps from 2010 to 2016. The surgical technique involved raising 2-limbed subcutaneous pedicle-based propellar flap over the contracture using the unburnt skin at the axillary and cubital fossa. The flap with both the limb thus raised was rotated by 90 degrees in the same direction and inserted into the defect.

Results

Nine patients including 6 patients with elbow and 3 patients with axillary contractures were included in this study. The mean degree of contracture in axilla and elbow was 78.3 degrees and 59.1 degrees, respectively. The functional results postoperatively were satisfactory. The mean postoperative degree of joint movements in axilla and elbow was 176.3 degrees and 173.6 degrees, respectively. No major complications were encountered. There was a mean period of 12 months of follow-up.

Conclusions

In cases where normal skin is still present on the axillary and cubital fossa with scar contracture caused by extensive burns, the subcutaneous propeller flap methods and their modifications should be considered one of the most useful versatile reconstruction methods. Namaste flap in addition to the advantages of subcutaneous pedicle propeller flap also negates the disadvantages caused by the use of split skin grafting of the donor area.
Retrospective Review and Prospective Follow-up of 85 Consecutive Patients Treated With a Novel Hepatic-derived Surgical Mesh for Hiatal Hernia Repair: Outcomes, Surgical Complications, and Revisions
Authors: Gillian George K. , Bansal Divya
Published: October 2019

This study examined outcomes, surgical complications, and revisions in patients treated with laparoscopic Nissen fundoplication for hiatal hernia and substantial gastroesophageal reflux disease. In total, 85 consecutive patients who underwent hernia repair with MIROMESH Biologic Matrix, a novel hepatic-derived surgical mesh served as subjects. Subjects were contacted by phone, consented, and participated in an Institutional Review Board-approved structured phone interview. Responses were acquired from 73 of the 85 patients. The gastroesophageal reflux disease health–related quality of life showed significant improvement postoperatively. Subjects reported high satisfaction with the procedure. The use of proton pump inhibitors was significantly reduced. Three minor complications were reported; these were quickly resolved without further sequelae. There were no mesh-related complications. No subjects reported further surgery. Placement of the surgical mesh, during surgery, to reinforce the hiatal repair was easy and safe. Excellent outcomes and no revisions a mean of 1.3 years after surgery suggest that a durable repair had been achieved.
A practical method for estimating coupling functions in complex dynamical systems
Authors: Tokuda Isao T. , Levnajic Zoran , Ishimura Kazuyoshi
Published: October 2019

A foremost challenge in modern network science is the inverse problem of reconstruction (inference) of coupling equations and network topology from the measurements of the network dynamics. Of particular interest are the methods that can operate on real (empirical) data without interfering with the system. One such earlier attempt (Tokudaet al.2007Phys. Rev. Lett.99, 064101. (doi:10.1103/PhysRevLett.99.064101)) was a method suited for general limit-cycle oscillators, yielding both oscillators' natural frequencies and coupling functions between them (phase equations) from empirically measured time series. The present paper reviews the above method in a way comprehensive to domain-scientists other than physics. It also presents applications of the method to (i) detection of the network connectivity, (ii) inference of the phase sensitivity function, (iii) approximation of the interaction among phase-coherent chaotic oscillators, and (iv) experimental data from a forced Van der Pol electric circuit. This reaffirms the range of applicability of the method for reconstructing coupling functions and makes it accessible to a much wider scientific community.

This article is part of the theme issue ‘Coupling functions: dynamical interaction mechanisms in the physical, biological and social sciences’.
Nonlinear phase coupling functions: a numerical study
Authors: Rosenblum Michael , Pikovsky Arkady
Published: October 2019

Phase reduction is a general tool widely used to describe forced and interacting self-sustained oscillators. Here, we explore the phase coupling functions beyond the usual first-order approximation in the strength of the force. Taking the periodically forced Stuart–Landau oscillator as the paradigmatic model, we determine and numerically analyse the coupling functions up to the fourth order in the force strength. We show that the found nonlinear phase coupling functions can be used for predicting synchronization regions of the forced oscillator.

This article is part of the theme issue ‘Coupling functions: dynamical interaction mechanisms in the physical, biological and social sciences’.
Synchronization transitions caused by time-varying coupling functions
Authors: Hagos Zeray , Stankovski Tomislav , Newman Julian , Pereira Tiago , McClintock Peter V. E. , Stefanovska Aneta
Published: October 2019

Interacting dynamical systems are widespread in nature. The influence that one such system exerts on another is described by a coupling function; and the coupling functions extracted from the time-series of interacting dynamical systems are often found to be time-varying. Although much effort has been devoted to the analysis of coupling functions, the influence of time-variability on the associated dynamics remains largely unexplored. Motivated especially by coupling functions in biology, including the cardiorespiratory and neural delta-alpha coupling functions, this paper offers a contribution to the understanding of effects due to time-varying interactions. Through both numerics and mathematically rigorous theoretical consideration, we show that for time-variable coupling functions with time-independent net coupling strength, transitions into and out of phase- synchronization can occur, even though the frozen coupling functions determine phase-synchronization solely by virtue of their net coupling strength. Thus the information about interactions provided by the shape of coupling functions plays a greater role in determining behaviour when these coupling functions are time-variable.

This article is part of the theme issue ‘Coupling functions: dynamical interaction mechanisms in the physical, biological and social sciences’.
Discovery of the spatial pattern of prickles on the stem of the rose and the mathematical model of the pattern
Authors: Amikura Kazuaki , Ito Hiroshi
Published: October 2019

Reproducible pattern is a key characteristic of organisms. Many developmental patterns are known that it is orchestrated by diffusion of the factors. Herein, we reported a novel patterning that seems to be controlled by diffusion factors. Although it looks like the prickles randomly emerge on the stem of rose, we deciphered patterns for the position of prickles with statistical data and proposed a mathematical model to explain the process via which the pattern emerged. By changing the model parameters, we reproduce another pattern on other plant species. This finding indicates that the patterns between many species are organized by similar systems. Moreover, although the pattern of organisms is often linked to its function, we consider the spatial pattern of prickles may have a function to play the role of prickles effectively. Further studies will clarify the role of prickles and reveal the entity of diffusive factors.
Adaptive zinc tolerance is supported by extensive gene multiplication and differences in cis-regulation of a CDF transporter in an ectomycorrhizal fungus
Authors: Ruytinx Joske , Coninx Laura , Op De Beeck Michiel , Arnauts Natascha , Rineau François , Colpaert Jan V.
Published: October 2019

Abiotic changes due to anthropogenic activities affect selection regimes for organisms. How trees and their mycorrhizal symbionts adapt to altered environments in heterogeneous landscapes is of great interest. With a global distribution and multiple adaptive phenotypes available,Suillus luteusis an excellent ectomycorrhizal model to study evolutionary dynamics of local adaptation. We assessed pathways of homeostasis and detoxification inS. luteusisolates, displaying contrasting Zn tolerance phenotypes to identify mechanisms underlying adaptive Zn tolerance. Using 30 randomly selected isolates sampled at metal contaminated and control sites, we documented Zn tolerance phenotypes, assessed the link with identified candidate genes and explored its genetic basis via targeted amplicon sequencing and qPCR. Zn tolerance phenotypes covering a continuum from Zn sensitive to hypertolerant were identified and inversely correlate with cellular Zn accumulation. Gene expression ofSlZnT2, encoding a putative Zn transporter explains 72% of the observed phenotypic variation.SlZnT2copy number varies among isolates and different promotor genotypes were identified. Rapid adaptation in this species is supported by the cumulative effect of gene copy number variation and differences in cis-regulation and might be triggered by environmental stress rather than being the result of standing variation.

Originality - significance statement

To the best of our knowledge, this is the first study linking genotypes to adaptive phenotypes in mycorrhizal fungi. It is unique in the way it combines evolutionary and functional genetics to allow a significant advance in the understanding of responses to environmental stress factors in general and, to soil metal pollution in particular. A better understanding of adaptive tolerance mechanisms in keystone symbiotic fungi is paramount for developing impactful phyto and mycoremediation strategies for metal polluted waste land and to predict the impact of future environmental change on mycorrhizal diversity and ecosystem functioning.
Computational Assessment of the Regulation-Modulating Potential for Noncoding Variants
Authors: Shi Fang-Yuan , Wang Yu , Huang Dong , Liang Yu , Liang Nan , Chen Xiao-Wei , Gao Ge
Published: October 2019

Large-scale genome-wide association and expression quantitative trait loci studies have identified multiple noncoding variants associated with genetic diseases via affecting gene expression. However, effectively and efficiently pinpointing causal variants remains a serious challenge. Here, we developed CARMEN, a novel algorithm to identify functional noncoding expression-modulating variants. Multiple evaluations demonstrated CARMEN’s superior performance over state-of-the-art tools. Its higher sensitivity and low false discovery rate enable CARMEN to identify multiple causal expression-modulating variants that other tools simply missed. Meanwhile, benefitting from extensive annotations generated, CARMEN provides mechanism hints on predicted expression-modulating variants, enabling effectively characterizing functional variants involved in gene expression and disease-related phenotypes. CARMEN scales well with the massive datasets and is available online as a Web server at http://carmen.gao-lab.org.
Mimicry embedding for advanced neural network training of 3D biomedical micrographs
Authors: Yakimovich Artur , Huttunen Moona , Samolej Jerzy , Clough Barbara , Yoshida Nagisa , Mostowy Serge , Frickel Eva , Mercer Jason
Published: October 2019

The use of deep neural networks (DNNs) for analysis of complex biomedical images shows great promise but is hampered by a lack of large verified datasets for rapid network evolution. Here we present a novel “mimicry embedding” strategy for rapid application of neural network architecture-based analysis of biomedical imaging datasets. Embedding of a novel biological dataset, such that it mimics a verified dataset, enables efficient deep learning and seamless architecture switching. We apply this strategy across various microbiological phenotypes; from super-resolved viruses toin vivoparasitic infections. We demonstrate that mimicry embedding enables efficient and accurate analysis of three-dimensional microscopy datasets. The results suggest that transfer learning from pre-trained network data may be a powerful general strategy for analysis of heterogeneous biomedical imaging datasets.
Conformational Plasticity of the ClpAP AAA+ Protease Couples Protein Unfolding and Proteolysis
Authors: Lopez Kyle E. , Rizo Alexandrea N. , Tse Eric , Lin JiaBei , Scull Nathaniel W. , Thwin Aye C. , Lucius Aaron L. , Shorter James , Southworth Daniel R.
Published: October 2019

The ClpAP complex functions as a “bacterial proteasome” that simultaneously unfolds and degrades proteins targeted for destruction. ClpA utilizes two AAA+ domains per protomer to power substrate unfolding and translocation into the ClpP proteolytic chamber. To understand this mechanism, we determined high-resolution structures of wildtype E. coli ClpAP in distinct substrate-bound states. ClpA forms a spiral with substrate contacts across both AAA+ domains, while protomers at the seam undergo nucleotide-specific rearrangements indicating a conserved rotary mechanism. ClpA IGL loops extend flexibly to bind the planar, heptameric ClpP surface and support a large ClpA-P rotation that re-orients the translocation channel. The symmetry mismatch is maintained at the spiral seam through bind and release states of the IGL loops, which appear precisely coupled to substrate translocation. Thus, ClpA rotates around the apical surface of ClpP to processively translocate substrate into the protease.
ModiBodies: A computational method for modifying nanobodies to improve their antigen binding affinity and specificity
Authors: Hacisuleyman Aysima , Erman Burak
Published: October 2019

Nanobodies are special derivatives of antibodies, which consist of only a single chain. Their hydrophilic side prevents them from having the solubility and aggregation problems of conventional antibodies, and they retain the similar size and affinity of the binding area to the antigen. Nanobodies have become of considerable interest for next-generation biotechnological tools for antigen recognition. They can be easily engineered due to their high stability and compact size. They have three complementarity determining regions, CDRs, which are enlarged to provide a similar binding surface to that of regular antibodies. The binding residues are more exposed to the environment. One common strategy to improve protein solubility is to replace hydrophobic residues with hydrophilic ones on the binding surface which contributes to both stability and solubility of nanobodies.[1] Here, we propose an algorithm that uses the 3D structures of protein-nanobody complexes as the initial structures and by successive mutations in the CDR domains to find optimum binding amino acids for hypervariable residues of CDRs to increase the binding affinity and nanobody selectivity. We used the MDM4-VH9 complex, (PDB id 2VYR), fructose-bisphosphate aldolase from Trypanosoma congolense, (PDB id 5O0W), and human lysozyme, (PDB id 4I0C). as benchmark studies and identified similar amino acid patterns in hypervariable residues of CDRs with experimentally optimized ones. According to this method, better binding nanobodies can be generated by using this algorithm in a short time. We suggest that this method can complement existing immune and synthetic library-based methods, without the need of experiments or large libraries.
Perivascular Adipose Tissue: Quantitative analysis by morphometry and stereology in rodents
Authors: Carneiro Felipe Demani , Mello Stephanie Christinne Sinder , Marques Emiliana Barbosa , Barros Rogerio Barbosa Magalhaes , Scaramello Christianne Bretas Vieira , Fernandes-Santos Caroline
Published: October 2019

The perivascular adipose tissue (PVAT) provides mechanical support to blood vessels and modulates vascular physiology in obesity. Our goal is to provide a reproductive protocol using morphometric and stereological tools to assess PVAT morphology. The thoracic aorta from male Wistar rats (n=6) and C57BL/6 mice (n=7) underwent routine histological procedures, and two independent observers analyzed the same set of digital images. Agreement and reproducibility were assessed. Both observers showed that the diameter of rat brown adipocytes is larger than mice (P<0.002) as expected, and that the number density (QA) of brown adipocytes is smaller in rats compared to mice (P<0.01). Considering lipid droplets, observer #1 reported that in rats they were larger (P<0.005) and had a higher volume density (VV) than mice (P=0.035), but observer #2 found the opposite for lipid droplet diameter (P=0.001). White adipocytes were not found in the PVAT. Bland-Altman plots demonstrated agreement and reproducibility between observers since the means are close to the main difference (bias) and within the 95% limits of agreement. In conclusion, the methodology proposed can quantify morphological aspects of the aorta PVAT in rodents. It is reproducible and can be performed by both expert and inexperienced researchers, once they know how to recognize the structures of interest to be measured.
Electrophysiological characterization of AtAMT1;4, an extraordinarily high affinity ammonium transporter from Arabidopsis thaliana
Authors: Bindel Nino , Neuhäuser Benjamin
Published: October 2019

In plants high affinity transport proteins mediate the essential transport of ammonium across membranes. In Arabidopsis thaliana six of these AMmonium Transporters (AMTs) are encoded on the genome. All of these show a unique expression pattern. While most AMTs are highly expressed in the root, AtAMT1;4 expression is limited to the pollen grains and the pollen tube. Here, we addressed the transport characteristics of AtAMT1;4 in the heterologous Xenopus laevis oocytes system. Two electrode voltage clamp measurements tagged AtAMT1;4 as an electrogenic high affinity ammonium transporter. The transport was saturable and showed extraordinarily high affinity for ammonium with a Km value lower than 10 µM.
Tissue-wide integration of mechanical cues promotes efficient auxin patterning
Authors: Ramos João R. D. , Maizel Alexis , Alim Karen
Published: October 2019

New plants organs form by local accumulation of auxin, which is transported by PIN proteins that localize following mechanical stresses. As auxin itself modifies tissue mechanics, a feedback loop between tissue mechanics and auxin patterning unfolds – yet the impact of tissue-wide mechanical coupling on auxin pattern emergence remains unclear. Here, we use a hybrid model composed of a vertex model for plant tissue mechanics, and a compartment model for auxin transport to explore the collective mechanical response of the tissue to auxin patterns and how it feeds back onto auxin transport. We compare a model accounting for a tissue-wide mechanical integration to a model where mechanical stresses are averaged out across the tissue. We show that only tissue-wide mechanical coupling leads to focused auxin spots, which we show to result from the formation of a circumferential stress field around these spots, self-reinforcing PIN polarity and auxin accumulation.
A synthetic peptide library for benchmarking crosslinking mass spectrometry search engines
Authors: Beveridge Rebecca , Stadlmann Johannes , Penninger Josef M. , Mechtler Karl
Published: October 2019

We have created synthetic peptide libraries to benchmark crosslinking mass spectrometry search engines for different types of crosslinker. The unique benefit of using a library is knowing which identified crosslinks are true and which are false. Here we have used mass spectrometry data generated from measurement of the peptide libraries to evaluate the most frequently applied search algorithms in crosslinking mass-spectrometry. When filtered to an estimated false discovery rate of 5%, false crosslink identification ranged from 5.2% to 11.3% for search engines with inbuilt validation strategies for error estimation. When different external validation strategies were applied to one single search output, false crosslink identification ranged from 2.4% to a surprising 32%, despite being filtered to an estimated 5% false discovery rate. Remarkably, the use of MS-cleavable crosslinkers did not reduce the false discovery rate compared to non-cleavable crosslinkers, results from which have far-reaching implications in structural biology. We anticipate that the datasets acquired during this research will further drive optimisation and development of search engines and novel data-interpretation technologies, thereby advancing our understanding of vital biological interactions.
Does all entrepreneurship matter? The contribution of entrepreneurial activity to economic growth
Authors: Ordeñana Xavier , Vera-Gilces Paul , Zambrano-Vera Jack , Amaya Adriana
Published: October 2019

Purpose

The purpose of this paper revisits the effect of entrepreneurship on economic growth.

Design/methodology/approach

Using a cross-country panel data set of 61 countries in the period 2002–2014, this paper empirically analyzes the differences in contribution to economic growth. Particularly, using an extension of the Cobb–Douglas production function, the authors show the role of entrepreneurship in developed and developing economies. Global entrepreneurship monitor data were used to estimate the proposed types of entrepreneurship.

Findings

Results indicate that economic growth can be explained by growth-oriented entrepreneurship, including developing economies. These results remain robust to a variety of specifications that include economic, social and cultural controls, and two ways of sorting countries by stage of development.

Originality/value

The authors split the total entrepreneurial activity (TEA) according to job expectations, in order to isolate the effect of entrepreneurial activity that is growth oriented (dynamic) and not (regular). Lastly, the empirical application presented comprises a more adequate timeframe to analyze the proposed relationship, determining possible differences for developed and developing economies.
Numerical analysis of free convection and entropy generation in a cavity using compact finite-difference lattice Boltzmann method
Authors: KhakRah HamidReza , Hooshmand Payam , Ross David , Jamshidian Meysam
Published: October 2019

Purpose

The purpose of this paper is to investigate the compact finite-difference lattice Boltzmann method is used to simulate the free convection within a cavity.

Design/methodology/approach

The finite-difference discretization method enables the numerical simulations to be run when there are non-uniform and curvilinear grids with a finer near-wall grid resolution. Furthermore, the high-order method is applied in the numerical approach, which makes it possible to go with relatively coarse mesh in respect to simulations, which used classical lattice Boltzmann method. The configuration of the cavity is set to sine-walled square. In addition, the cavity is filled with Al2O3-water nanofluid, and the Koo–Kleinstreuer–Li model is used to estimate the properties of nanofluid.

Findings

The nanoparticle (Al2O3) concentration in the base fluid (water) is considered in a range of 0-0.04. The nanofluid flow and heat transfer are investigated in laminar regime with Rayleigh number in the range of 103-106. The second law analysis is used to study the effects of different governing parameters on the local and volumetric entropy generation. The Rayleigh number, configuration of the cavity and nanoparticle concentration are considered as the governing parameters. The results are mainly focused on the flow structure, temperature field, local and volumetric entropy generation and heat transfer performance.

Originality/value

The originality of this study is using of a modern numerical method supported by an accurate prediction for nanofluid properties to simulate the flow and heat transfer during natural convection in a cavity.
Bank diversity and SME innovation: evidence from China
Authors: Li Hongyu , Wu Junjie , Lu Zhiqiang
Published: October 2019

Purpose

The purpose of this paper is to examine the relationship between bank diversity and small- and medium-sized enterprise (SME) firm innovation in China to evaluate the impact of recent bank deregulation.

Design/methodology/approach

Using a large data set that includes 8,143 firm-year observations of 1,122 listed SME firms in China and baseline and robustness regression analyses, the authors identify how bank diversity affects firm innovation and via what economic mechanisms. Potential endogeneity problems are considered and addressed in the design and analysis to minimize research bias.

Findings

The authors find robust evidence that bank diversity improves firm innovation. Specifically, the findings suggest that the positive effects of bank diversity on firm innovation are only significant for the firms which are more external finance dependent, have fewer growth opportunities and/or located in the provinces having low financial market development.

Originality/value

This study provides novel evidence and insights into the relationship between banking market structure and the determinants of firm innovation in the Chinese context, as a result of China’s banking deregulation.
Delving into children’s travel dreams: a qualitative investigation
Authors: Demirdelen Derya , Alrawadieh Ziad , Zareer Ahmed , Kizilirmak Ismail
Published: October 2019

Purpose

Drawing on a qualitative study approach using data collected from children in a primary school in Marmaris, Turkey, this study aims to intend to understand children’s vacation perceptions and preferences.

Design/methodology/approach

Students were asked to write a short composition describing where they would love to go for vacation (either in Turkey or abroad), why they would choose that destination(s) in particular and what they would do while on vacation. A task-based research technique was adopted, which is more adequate for research involving children participants. A total of 103 compositions were collected and a thematic content analysis was conducted. This approach has been widely used in tourism and hospitality research.

Findings

The findings revealed that children can clearly express their perceptions and preferences with regard to leisure activities. The majority of children wanted to visit overseas destinations (specifically, the USA, Germany and France), while a significant portion preferred local destinations within Turkey (specifically, Istanbul and Antalya). The desire for recreation and holiday, exploring new places and trying local foods and visiting families and relatives were identified as key travel motivations.

Originality/value

A key contribution of the current study lies in the fact that it adds to a research stream that shifts attention to insights gained directly from children rather relying on parents as a proxy. The paper has some theoretical and empirical implications.
Joining of AA6061 to polyvinyl chloride via hot extrusion
Authors: Abdullah Isam Tareq , Hussein Sabah Khammass , Hussein Abbas Khammas
Published: October 2019

Purpose

The purpose of this paper is to join aluminium alloy AA6061 with polyvinyl chloride (PVC) sheets using the friction spot technique.

Design/methodology/approach

The AA6061 specimen was drilled with a semi-conical hole and put over the PVC specimen with a lap configuration. A friction spot technique was used to generate the required heat to melt and extrude the PVC through the aluminium hole. In this study, three process parameters were used: time, plunging depth and rotating speed of the tool. Thermal finite element model was built to analyse the process temperature. Effect of the process parameters on the joint shear strength and temperature was analysed using the design of experiments method. The microstructure investigation of the joint cross section was examined.

Findings

The input heat melted and extruded the polymer into the aluminium hole with the aid of tool pressure. A mechanical interlock was observed at the interface line between the polymer and aluminium. The scattered aluminium fragments into the molten polymer increased the shear strength of the joint. The hole diameter exhibited the highest effect on the joint strength compared with the other parameters. Specimen of minimum hole diameter recorded the maximum shear strength of 224 MPa. The proposed model gave a good agreement with the experimental data.

Originality/value

For the first time, the PVC was joined with AA6061 by the hot extrusion using the friction spot technique. The shear strength of joint reached 7.5 times of the base material (PVC).
Repatriation: a qualitative study of repatriates after returning from China assignments
Authors: Kimber John A.
Published: October 2019

Purpose

Companies expend significant resources on global assignees’ success during deployment. However, the broader repatriation experience of organizational expatriates and their families, beyond securing employment, is still largely unexplored. Thus, the purpose of this paper, an exploratory study, is to describe the repatriation experience of five US Christian repatriates who returned to the USA after long-term expatriate assignments in China.

Design/methodology/approach

A qualitative approach was employed, and data were collected through five open-ended interviews with US Christian repatriates, focusing on their social networks and family repatriation experiences.

Findings

Upon repatriation, most global assignees received assistance with relocation and securing stateside employment but no assistance with readjustment issues for themselves or their accompanying family members. Most found repatriation the most difficult part of the assignment, and home churches were of little assistance. The findings support the deterioration of home social networks during longer assignments and extend the literature’s findings to the expatriate spouse and families.

Originality/value

This exploratory study addresses the experiences of Christian US repatriates and their social support through work and non-work home social networks. The findings highlight the importance of intentional efforts by repatriates and their families to strengthen their home social connections in order to minimize repatriation difficulties.
Examining the role of customer engagement in augmenting referral value
Authors: Sahi Gurjeet Kaur , Devi Rita , Dash Satya Bhusan
Published: October 2019

Purpose

The purpose of this paper is to examine the impact of a customer engagement-enabling platform on a value captured by the firm and value acquired by the customer. It explores the relevance of relational and expertise value for customers during the engagement process so as to ensure positive referrals about the service provider.

Design/methodology/approach

Using a sample of 482 students, the study examines the customer engagement efforts of professional institutes that provide training to prepare for the civil service examinations of the Union Public Service Commission. The survey is confined to central areas of New Delhi, India. Statistical techniques including confirmatory factor analysis and structural equation modelling are used to analyse the data, and reliability and validity tests are performed.

Findings

The findings reveal the indispensable role of service providers as creators of a meaningful effective learning process and of interpersonal relations with customers for generating more business through customer referrals.

Research limitations/implications

The study validated the moderating role of relational value between customers’ expertise value and their referrals on the basis of motivation theory, which asserts that customers’ motivation to contribute to the organisation is driven by the individuals’ extrinsic relational need for belongingness, acceptance by like-minded individuals, and feedback, recognition and respect from employees of the organisation.

Originality/value

The study contributes to the existing literature by integrating the well-developed social exchange and motivation theory so as to investigate the factors that propel customers’ positive word of mouth for the service provider.
Environmental management accounting practices and organizational performance: the mediating effect of information system
Authors: Mohd Fuzi Nursyazwani , Habidin Nurul Fadly , Janudin Sharul Effendy , Ong Sharon Yong Yee , Ku Bahador Ku Maisurah
Published: October 2019

Purpose

The purpose of this paper is to examine the mediating effect of information system (IS) on the relationship between environmental management accounting practices (EMAP) and organizational performance (OPM) for Malaysian manufacturing industry.

Design/methodology/approach

This study is based on survey data collected from 395 manufacturing companies in Malaysia. Validity and reliability analyses were performed using IBM SPSS and structural equation modeling was used to test the research hypotheses.

Findings

The results indicated that EMAP positively and significantly to IS and OPM. This study also found that IS partially mediates the relationship between EMAP and OPM. This study also found that IS partially mediates the relationship between EMAP and OPM.

Research limitations/implications

This study has a number of limitations that need to be addressed in future research. First, the population and sample of survey respondents are only targeted in the Malaysian manufacturing industry. Second, this research only uses the survey technique and is conducted in the Malaysian manufacturing industry. Third, the limitation of this study would concern the difficulty to find EMAP and IS relationship literatures in the Malaysian manufacturing industry. However, the researchers consider that there is greater scope for investigation on the EMAP, IS and OPM relationships for Malaysian manufacturing industry.

Originality/value

This study contributes to the existing body of knowledge by examining the mediating effect of IS on the relationship between EMAP and OPM for Malaysian manufacturing industry. Thus, it is expected that the results of this study have given valuable insight of the relationship between EMAP, IS on OPM for Malaysian manufacturing industry.
Promoting the mental and physical wellbeing of people with mental health difficulties through social enterprise
Authors: Hartley Sandra Elaine , Yeowell Gillian , Powell Susan Caron
Published: October 2019

Purpose

Interventions that promote both mental and physical wellbeing have been advocated for people with mental health difficulties, as they have been found to engage less in healthy behaviours and have lower levels of physical fitness. However, no optimal approach to facilitate this undertaking has been identified. The purpose of this paper is to explore the experiences of people with psychological distress who accessed a social enterprise that fosters the building of positive social networks in the community, as part of a personalised recovery programme. The intention was to gain an insight into its therapeutic effect in relation to mental and physical health.

Design/methodology/approach

An exploratory survey design was undertaken with a purposive sample of 50 individuals who had attended the enterprise. Descriptive statistics and thematic analysis were employed to analyse the data from both closed and open-ended questions.

Findings

The wellbeing service appeared to provide a supportive environment that offered people access to social networks through their participation in local services and activities. Fostering participants’ active participation, connection building and the ability to make meaningful contributions helped to facilitate health behaviours that had a positive impact on their health and wellbeing.

Originality/value

This study highlights the potential role of a social enterprise in optimising the social context for promoting the health and wellbeing of people with mental health difficulties.