bluuebunny/crossref_metadata_2025 huggingface dataset:
Exposures to Air Pollution and Risk of Acute-onset Placental Abruption
Authors: Ananth Cande V. , Kioumourtzoglou Marianthi-Anna , Huang Yongmei , Ross Zev , Friedman Alexander M. , Williams Michelle A. , Wang Shuang , Mittleman Murray A. , Schwartz Joel
Published: June 2018

Background:

Despite abruption’s elusive etiology, knowledge of triggers that precede it by just a few days prior to delivery may help to understand the underpinnings of this acute obstetrical complication. We examine whether air pollution exposures immediately preceding delivery are associated with acute-onset abruptions.

Methods:

We applied a bidirectional, time-stratified, case-crossover design to births with an abruption diagnosis in New York City, 2008–2014. We measured ambient fine particulate matter (PM2.5) and nitrogen dioxide (NO2). We fit distributed lag nonlinear models based on conditional logistic regression to evaluate individual exposure and cumulative exposures over lags 0–7 days before abruption, adjusted for temperature and relative humidity (similar lags to the main exposures).

Results:

We identified 1,190 abruption cases. We observed increased odds of abruption for exposure to PM2.5 (per 10 μg/m3) on lag day 3 (odds ratio [OR] 1.19, 95% confidence interval [CI] = 0.98, 1.43), lag day 4 (OR 1.21, 95% CI = 1.01, 1.46), and lag day 5 (OR 1.17, 95% CI = 1.03, 1.33). Similarly, the odds of abruption increased with exposure to NO2 (per 5 ppb) on lag day 3 (OR 1.16, 95% CI = 0.98, 1.37), lag day 4 (OR 1.19, 95% CI = 1.02, 1.39), and lag day 5 (OR 1.16, 95% CI = 1.05, 1.27). Exposures to PM2.5 and NO2 at other lags, or cumulative exposures, were not associated with abruption of acute onset.

Conclusions:

This case-crossover study showed evidence of an association between short-term ambient air pollution exposures and increased abruption risk of acute onset.
Challenges of Conducting Research With Young Offenders With Traumatic Brain Injury
Authors: O'Rourke Conall , Templeton Michelle , Cohen Miriam H. , Linden Mark A.
Published: June 2018

The purpose of this commentary is to highlight the challenges encountered when conducting research with young offenders. This is drawn from the first-hand experience of 3 researchers working on separate projects within this environment. Young offenders present as a complex clinical population with high levels of illiteracy, substance abuse, and mental health issues. Significant planning is therefore required before working with this group. Consideration must be given to the heterogeneity of prison populations alongside the potential limitations of datacollection methods, in particular, reliance on self-report. The capacity of young offenders to comprehend and effectively engage with research is also of concern, posing issues of both a practical and ethical nature. The absence of a consistent “research culture” within prison environments poses further practical challenges, potentially also placing significant burden on both researchers and prison resources. The challenges discussed in this article may help inform future studies in the area and emphasize the need for greater critical reflection among researchers conducting work of this type.
Rehabilitation Trajectories and Outcomes in Individuals With Mild Traumatic Brain Injury and Psychiatric Histories: A TRACK-TBI Pilot Study
Authors: Bertisch Hilary , Satris Gigi , Temkin Nancy , Barber Jason , Manley Geoffrey T.
Published: June 2018

Objective:

To determine differences in rehabilitation trajectories and return to work (RTW) and social outcomes in individuals with mild traumatic brain injury (mTBI) with and without significant psychiatric histories at index hospitalization.

Setting:

Three level 1 trauma centers participating in the Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) consortium.

Participants:

A total of 305 individuals with index mTBI enrolled in the TRACK-TBI pilot project.

Design:

Secondary analysis of data from the TRACK-TBI pilot study.

Main Measures:

Chart review and patient/family interview at emergency department (ED) admission, ED clinical data, ED discharge plan, functional interview data at 3- and 6-month outcomes, Trail Making Tests, the Wechsler Adult Intelligence Scale, Fourth Edition, Processing Speed Index, the California Verbal Learning Test, Second Edition, and the Craig Handicap Assessment and Reporting Technique.

Results:

Controlling for neurological history and CT lesion at ED admission, participants with and without psychiatric histories did not differ in terms of treatment, return to work, or reported social function. Individuals with psychiatric histories demonstrated lower processing speed and reported reduced satisfaction with occupational function at outcome.

Conclusions:

Individuals with mTBI and psychiatric histories may require specialized rehabilitation planning to address increased risk for cognitive difficulties and occupational dissatisfaction at outcome. CT lesion may independently influence outcomes.
Wave Intensity Analysis of Right Ventricular Function during Pulsed Operation of Rotary Left Ventricular Assist Devices
Authors: Bouwmeester J. Christopher , Park Jiheum , Valdovinos John , Bonde Pramod
Published: June 2018

Changing the speed of left ventricular assist devices (LVADs) cyclically may be useful to restore aortic pulsatility; however, the effects of this pulsation on right ventricular (RV) function are unknown. This study investigates the effects of direct ventricular interaction by quantifying the amount of wave energy created by RV contraction when axial and centrifugal LVADs are used to assist the left ventricle. In 4 anesthetized pigs, pressure and flow were measured in the main pulmonary artery and wave intensity analysis was used to identify and quantify the energy of waves created by the RV. The axial pump depressed the intensity of waves created by RV contraction compared with the centrifugal pump. In both pump designs, there were only minor and variable differences between the continuous and pulsed operation on RV function. The axial pump causes the RV to contract with less energy compared with a centrifugal design. Diminishing the ability of the RV to produce less energy translates to less pressure and flow produced, which may lead to LVAD-induced RV failure. The effects of pulsed LVAD operation on the RV appear to be minimal during acute observation of healthy hearts. Further study is necessary to uncover the effects of other modes of speed modulation with healthy and unhealthy hearts to determine if pulsed operation will benefit patients by reducing LVAD complications.
Quality of Life in Non-Muscle-Invasive Bladder Cancer Survivors
Authors: Jung Ahrang , Nielsen Matthew E. , Crandell Jamie L. , Palmer Mary H. , Bryant Ashley Leak , Smith Sophia K. , Mayer Deborah K.
Published: June 2018

Background

Non-muscle-invasive bladder cancer (NMIBC) represents approximately 75% of newly diagnosed patients with bladder cancer. Non-muscle-invasive bladder cancer survivors have unique chronic burdens including frequent recurrences, repeated surveillance cystoscopies and treatments, and the highest lifetime medical cost per person among all cancers.

Objective

The purpose of this study was to summarize studies assessing quality of life (QOL) in NMIBC survivors.

Methods

The literature from January 2005 to March 2017 found in PubMed, CINAHL, and PsycINFO databases was reviewed systematically. Inclusion criteria were as follows: (1) research about NMIBC survivors, (2) outcomes included QOL, (3) original research article published in peer-reviewed journals, and (4) published in English.

Results

A total of 15 studies were included: 14 quantitative studies and 1 mixed-methods study. Non-muscle-invasive bladder cancer survivors had significantly lower QOL compared with the general population, especially in fatigue, physical and role functioning, and mental health. Repeated transurethral resections and intravesical treatments were associated with impaired physical function and mental health. Most NMIBC survivors had concerns of urinary and bowel problems and sexual function.

Conclusion

Despite a good prognosis, NMIBC and its treatment have a significant impact on QOL in survivors. The findings showed large burdens in NMIBC survivors and suggest that further research is needed to better understand potential opportunities to improve QOL in this population.

Implications for Practice

Oncology nurses are in the critical position for assessing symptoms and concerns. Oncology nurses should pay special attention to NMIBC survivors who have unique symptoms and burden with the aim of improving survivors' QOL.
Organic Labeling Policy
Authors: Dolick Kirstin N. , Pham Linh D. , Mendes Candido de Oliveira Gabriella , Savaiano Dennis A.
Published: June 2018

In the United States, organic label claims are regulated by the US Department of Agriculture through a unique and complex 3-tiered categorization. Organic labeling rules were first introduced on a national scale in the 1990s. Over the last 3 decades, the organic market has continued to attract more consumers and manufacturers. Other nations currently regulate 'organic” claims allowing for the international trade of products using only 1 category. The purpose of this article is to describe 3 categories currently used in the United States and to discuss the potential of reforming the current system to provide clarity for consumers and enhance international trade.
Clinical, Dopaminergic, and Metabolic Correlations in Parkinson Disease
Authors: Liu Feng-Tao , Ge Jing-Jie , Wu Jian-Jun , Wu Ping , Ma Yilong , Zuo Chuan-Tao , Wang Jian
Published: June 2018

Purpose

Neuroimaging indicators of Parkinson disease have been developed and applied in clinical practices. Dopaminergic imaging reflects nigrostriatal dopaminergic dysfunction, and metabolic network imaging offers disease-related metabolic changes at a system level. We aimed to elucidate the association between Parkinsonian symptoms and neuroimaging, and interactions between different imaging techniques.

Methods

We conducted a dual-tracer PET study for the combined assessments of dopaminergic binding (11C-CFT) and glucose metabolism (18F-FDG) in 103 participants with Parkinson disease (65 male and 38 female subjects). The detailed clinical rating scores were systematically collected in all members. The interactions among dopaminergic bindings, metabolic changes, and clinical manifestations were evaluated at voxel, regional, and network levels.

Results

Striatal DAT binding correlated with akinesia-rigidity (P < 0.001) but not with tremor; the metabolic PET imaging, nonspecific to the dopaminergic dysfunction, disclosed a set of brain regions correlating with the cardinal symptoms, including tremor. In addition, the unilateral symptom correlated with the contralateral nigrostriatal dopamine loss, but with bilateral metabolic changes, suggesting their differences in the application of disease-related mechanistic studies. Further imaging-imaging correlation study revealed that dopaminergic dysfunction correlated with widely distributed metabolic changes in Parkinson disease, and the modest correlations supported the findings on the clinical-imaging correlation.

Conclusions

In this dual-tracer PET study, we demonstrated the robust interactions among dopaminergic dysfunction, metabolic brain changes and clinical manifestations at voxel, regional, and network levels. Our findings might promote the understanding in the proper application of dopaminergic and metabolic PET imaging in Parkinson disease and offer more evidence in support of Parkinsonian pathophysiological mechanisms.
A Rare Case of Retroperitoneal Follicular Dendritic Cell Sarcoma Identified by 99mTc-HYNIC-TOC SPECT/CT
Authors: Li Yi , Xu Xiaoping , Xu Junyan , Huang Dan
Published: June 2018

Follicular dendritic cell sarcoma is a very rare neoplasm, which is not lymphoma, but originates from a type of immune cells called follicular dendritic cells. We presented a 37-year-old woman who has suffered from obstructive jaundice, weight loss and right upper abdominal pain for 2 months. The contrast CT revealed masses located in the region of pancreatic head and lots of enlarged retroperitoneal lymph nodes, both of which were enhanced on the artery phase of CT images. Meanwhile, 99mTc-HYNIC-TOC SPECT/CT revealed high activity in the corresponding lesions. After biopsy, the masses were pathologically confirmed as retroperitoneal follicular dendritic cell sarcoma.
Pretest Scores Uniquely Predict 1-Year-Delayed Performance in a Simulation-Based Mastery Course for Central Line Insertion
Authors: Diederich Emily , Thomas Laura , Mahnken Jonathan , Lineberry Matthew
Published: June 2018

Introduction

Within simulation-based mastery learning (SBML) courses, there is inconsistent inclusion of learner pretesting, which requires considerable resources and is contrary to popular instructional frameworks. However, it may have several benefits, including its direct benefit as a form of deliberate practice and its facilitation of more learner-specific subsequent deliberate practice. We consider an unexplored potential benefit of pretesting: its ability to predict variable long-term learner performance.

Methods

Twenty-seven residents completed an SBML course in central line insertion. Residents were tested on simulated central line insertion precourse, immediately postcourse, and after between 64 and 82 weeks. We analyzed pretest scores' prediction of delayed test scores, above and beyond prediction by program year, line insertion experiences in the interim, and immediate posttest scores.

Results

Pretest scores related strongly to delayed test scores (r = 0.59, P = 0.01; disattenuated ρ = 0.75). The number of independent central lines inserted also related to year-delayed test scores (r = 0.44, P = 0.02); other predictors did not discernibly relate. In a regression model jointly predicting delayed test scores, pretest was a significant predictor (β = 0.487, P = 0.011); number of independent insertions was not (β = 0.234, P = 0.198).

Conclusions

This study suggests that pretests can play a major role in predicting learner variance in learning gains from SBML courses, thus facilitating more targeted refresher training. It also exposes a risk in SBML courses that learners who meet immediate mastery standards may be incorrectly assumed to have equal long-term learning gains.
Alevin efficiently estimates accurate gene abundances from dscRNA-seq data
Authors: Srivastava Avi , Malik Laraib , Smith Tom , Sudbery Ian , Patro Rob
Published: June 2018

We introduce alevin, a fast end-to-end pipeline to process droplet-based single cell RNA sequencing data, which performs cell barcode detection, read mapping, unique molecular identifier deduplication, gene count estimation, and cell barcode whitelisting. Alevin’s approach to UMI deduplication accounts for both gene-unique reads and reads that multimap between genes. This addresses the inherent bias in existing tools which discard gene-ambiguous reads, and improves the accuracy of gene abundance estimates.
A quasi-integral controller for adaptation of genetic modules to variable ribosome demand
Authors: Huang Hsin-Ho , Qian Yili , Del Vecchio Domitilla
Published: June 2018

The behavior of genetic circuits is often poorly predictable. A gene’s expression level is not only determined by the intended regulators, but also largely dictated by changes in ribosome availability imparted by activation or repression of other genes. To address this problem, we design a quasi-integral biomolecular feedback controller that enables the expression level of any gene of interest (GOI) to adapt to changes in available ribosomes. The feedback is implemented through a synthetic small RNA (sRNA) that silences the GOI’s mRNA, and uses orthogonal extracytoplasmic function (ECF) sigma factor to sense the GOI’s translation and to actuate sRNA transcription. Without the controller, the expression level of the GOI is reduced by 50% when a resource competitor is activated. With the controller, by contrast, gene expression level is practically unaffected by the competitor. This feedback controller allows adaptation of genetic modules to variable ribosome demand and thus aids modular construction of complicated circuits.
Age affects myosin relaxation states in skeletal muscle fibers of female but not male mice
Authors: Phung Lien A. , Karvinen Sira M. , Colson Brett A. , Thomas David D. , Lowe Dawn A.
Published: June 2018

The recent discovery that myosin has two distinct states in relaxed muscle – disordered relaxed (DRX) and super-relaxed (SRX) – provides another factor to consider in our fundamental understanding of the aging mechanism in skeletal muscle, since myosin is thought to be a potential contributor to dynapenia. The primary goal of this study was to determine the effects of age on DRX and SRX states and to examine their sex specificity. We have used quantitative fluorescence microscopy of the fluorescent nucleotide analog 2′/3′-O-(N-methylanthraniloyl) ATP (mantATP) to measure single-nucleotide turnover kinetics of myosin in skinned skeletal muscle fibers under relaxing conditions. We examined changes in DRX and SRX in response to the natural aging process by measuring the turnover of mantATP in skinned fibers isolated from psoas muscle of adult young (3-4 months old) and aged (26-28 months old) C57BL/6 female and male mice. Fluorescence decays were fitted to a multi-exponential decay function to determine both the time constants and mole fractions of fast and slow turnover populations, and significance was analyzed by a t-test. We found that in females, both the DRX and SRX lifetimes of myosin ATP turnover at steady state were shorter in aged muscle fibers compared to young muscle fibers (p≤0.033). However, there was no significant difference in relaxation lifetime of either DRX (p=0.202) or SRX (p=0.804) between young and aged male mice. No significant effects were measured on the mole fractions (populations) of these states, as a function of sex or age (females, p=0.100; males, p=0.929). The effect of age on the order of myosin heads at rest and their ATPase function is sex specific, affecting only females. These findings provide new insight into the molecular factors and mechanisms that contribute to aging muscle dysfunction in a sex-specific manner.
A functional study of all 40C. elegansinsulin-like peptides
Authors: Zheng Shanqing , Chiu Hilton , Boudreau Jeffrey , Papanicolaou Tony , Bendena William , Chin-Sang Ian
Published: June 2018

The human genome encodes ten insulin-like genes, whereas theC. elegansgenome remarkably encodes forty insulin-like genes. The roles of insulin/insulin-like peptide ligands (INS) inC. elegansare not well understood. The functional redundancy of the forty INS genes makes it challenging to address their functions by using knock out strategies. Here, we individually overexpressed each of the fortyinsgenes pan-neuronally, and monitored multiple phenotypes including: L1 arrest life span, neuroblast divisions under L1 arrest, dauer formation and fat accumulation, as readouts to characterize the functions of each INSin vivo. Of the 40 INS peptides, we found functions for 35 INS peptides and functionally categorized each as agonists, antagonists or of pleiotropic function. In particular, we found that 9 of 16 agonistic INS peptides shortened L1 arrest life span and promoted neuroblast divisions during L1 arrest. Our study revealed that a subset of β-class INS peptides that contain a distinct F peptide sequence are agonists. Our work is the first to categorize the structures of INS peptides and relate these structures to the functions of all forty INS peptidesin vivo. Our findings will promote the study of insulin function on development, metabolism, and aging-related diseases.

Author Summary

Insulin and insulin-like growth factors are found in all animals and regulate many physiological and developmental processes. The human genome has 10 insulin-like peptides including the well characterized insulin hormone. The nematodeC. eleganshas 40 insulin-like (INS) peptide genes. All 40 INS peptides have been knocked out but no single INS gene knock out resembles the loss of theC. elegansinsulin receptor suggesting that the other INS peptides can compensate when one INS is lost. We have used a genetic approach to overexpress each of the 40 INS peptides inC. elegansand have identifiedin vivofunction for 35 of the 40 INS peptides. Like the human insulin and IGF-1,C. elegansINS peptides are derived from a precursor protein and we have shown that INS peptides with an associated peptide called the F peptide are strong activators of theC. elegansinsulin-like receptor. We also identified several INS peptides that inhibit the insulin-like receptor and these inhibitory INS peptides may have therapeutic potential.
TGFβ blocks IFNα/β release and tumor rejection in spontaneous mammary tumors
Authors: Guerin Marion V. , Regnier Fabienne , Feuillet Vincent , Vimeux Lene , Weiss Julia M. , Bismuth Georges , Altan-Bonnet Gregoire , Guilbert Thomas , Thoreau Maxime , Finisguerra Veronica , Donnadieu Emmanuel , Trautmann Alain , Bercovici Nadège
Published: June 2018

Type I interferons (IFN) are being rediscovered as potent anti-tumoral agents. Activation of the STimulator of INterferon Genes (STING) by DMXAA can induce a strong production of IFNα/β and the rejection of transplanted primary tumors. In the present study, we addressed whether targeting STING with DMXAA also leads to the regression of spontaneous MMTV-PyMT mammary tumors. We show that these tumors are refractory to DMXAA-induced regression. This is due to a blockade in the phosphorylation of IRF3 and the ensuing IFNα/β production. Mechanistically, we identified TGFβ abundant in spontaneous tumors, as a key molecule limiting this IFN-induced-tumor regression by DMXAA. Finally, blocking TGFβ restores the production of IFNα by activated MHCII+tumor-associated macrophages, and enables tumor regression induced by STING activation. On the basis of these findings, we propose that type I IFN-dependent cancer therapies could be greatly improved by combinations including the blockade of TGFβ.
Policy driven changes in animal research practices: mapping researchers’ attitudes towards animal-free innovations using the Netherlands as an example
Authors: Bressers S. , van den Elzen H. , Gräwe C. , van den Oetelaar D. , Postma P.H.A. , Schoustra S.K.
Published: June 2018

Reducing the number of animals used in experiments has become a priority for the governments of many countries. For these reductions to occur, animal-free alternatives must be made more available and, crucially, must be embraced by researchers. We conducted an international online survey for academics in the field of animal science (N=367) to explore researchers’ attitudes towards the implementation of animal-free innovations.

Through this survey we address three key questions. The first question is whether scientists who use animals in their research consider governmental goals for animal-free innovations achievable and whether they would support such goals. Secondly, responders were asked to rank the importance of ten roadblocks that could hamper the implementation of animal-free innovations. Finally, responders were asked whether they would migrate (either themselves or their research) if increased animal research regulations in their country of residence restricted their research. While nearly half (40%) of the responders support governmental goals, the majority (71%) of researchers did not consider such goals achievable in their field within the near future. In terms of roadblocks for implementation of animal-free methods, ∼80% of the responders considered ‘reliability’ as important, making it the most highly ranked roadblock. However, all other roadblocks were reported by the majority of responders as somewhat important, suggesting that they must also be considered when addressing animal-free innovations. Importantly, a majority reported that they would consider migration to another country in response to restrictive animal research policy. Thus, governments must consider the risk of researchers migrating to other institutes, states or countries, leading to a ‘brain-drain’ if policies are too strict or suitable animal-free alternatives are not available. Our findings suggest that development and implementation of animal-free innovations are hampered by multiple factors. We outline three pillars concerning education, governmental influence and data sharing, the implementation of which may help to overcome these roadblocks to animal-free innovations.
Human long intrinsically disordered protein regions are frequent targets of positive selection
Authors: Afanasyeva Arina , Bockwoldt Mathias , Cooney Christopher R. , Heiland Ines , Gossmann Toni I.
Published: June 2018

Intrinsically disordered regions occur frequently in proteins and are characterized by a lack of a well-defined three-dimensional structure. Although these regions do not show a higher order of structural organization, they are known to be functionally important. Disordered regions are rapidly evolving, largely attributed to relaxed purifying selection and an increased role of genetic drift. It has also been suggested that positive selection might contribute to their rapid diversification. However, for our own species, it is currently unknown whether positive selection has played a role during the evolution of these protein regions. Here, we address this question by investigating the evolutionary pattern of more than 6600 human proteins with intrinsically disordered regions and their ordered counterparts. Our comparative approach with data from more than 90 mammalian genomes uses a priori knowledge of disordered protein regions, and we show that this increases the power to detect positive selection by an order of magnitude. We can confirm that human intrinsically disordered regions evolve more rapidly, not only within humans but also across the entire mammalian phylogeny. They have, however, experienced substantial evolutionary constraint, hinting at their fundamental functional importance. We find compelling evidence that disordered protein regions are frequent targets of positive selection and estimate that the relative rate of adaptive substitutions differs fourfold between disordered and ordered protein regions in humans. Our results suggest that disordered protein regions are important targets of genetic innovation and that the contribution of positive selection in these regions is more pronounced than in other protein parts.
Nucleus Assembly and Import in Xenopus laevis Egg Extract
Authors: Chen Pan , Levy Daniel L.
Published: June 2018

Xenopus egg extract represents a powerful cell-free biochemical tool for studying organelle assembly and function. Large quantities of cytoplasm can be isolated, and biochemical manipulation of extract composition and cell cycle state is relatively straightforward. In this protocol, we describe the reconstitution of nuclear assembly by adding a chromatin source to interphasic X. laevis egg extract. Intact nuclei assemble within 30–45 min of initiating the reaction, followed by nuclear growth. We also describe methods for imaging and quantifying nuclear import kinetics. Recombinant proteins or small molecules of interest can be added to the extract before or after nuclear assembly, and immunodepletion allows for removal of specific proteins from the extract. This approach will continue to inform mechanisms of nuclear assembly, nuclear pore complex assembly and function, nucleocytoplasmic transport, DNA replication, nuclear envelope breakdown, and nuclear size and shape regulation.
Preparation of Antibody Using Caprylic Acid
Authors: Fishman Jordan B. , Berg Eric A.
Published: June 2018

Caprylic acid has been used to enrich IgG from serum, ascites, and cell culture supernatants by precipitating the non-IgG serum proteins. By precipitating all of the unwanted serum proteins rather than the antibodies, the tendency of antibodies to aggregate when precipitated is avoided. This method should not be used with antibody sources that contain low concentrations of antibody, such as many cell culture supernatants, owing to the potential loss of high-affinity antibodies, which may be bound by the caprylic acid. After centrifugation, IgG remains in the supernatant, which can be used as the starting material for the next step in a multistep antibody purification protocol.
Assembly of Spindles and Asters in Xenopus Egg Extracts
Authors: Field Christine M. , Mitchison Timothy J.
Published: June 2018

Here, we provide methods for assembly of mitotic spindles and interphase asters in Xenopus laevis egg extract, and compare them to spindles and asters in the egg and zygote. Classic “cycled” spindles are made by adding sperm nuclei to metaphase-arrested cytostatic factor (CSF) extract and inducing entry into interphase extract to promote nucleus formation and DNA replication. Interphase nuclei are then converted to cycled spindles arrested in metaphase by addition of CSF extract. Kinetochores assemble in this reaction and these spindles can segregate chromosomes. CSF spindles are made by addition of sperm nuclei to CSF extract. They are less physiological and lack functional kinetochores but suffice for some applications. Large interphase asters are prepared by addition of artificial centrosomes or sperm nuclei to actin-intact egg extract. These asters grow rapidly to hundreds of microns in radius by branching microtubule nucleation at the periphery, so the aster as a whole is a network of short, dynamic microtubules. They resemble the sperm aster after fertilization, and the asters that grow out of the poles of the mitotic spindle at anaphase. When interphase asters grow into each other they interact and assemble aster interaction zones at their shared boundary. These zones consist of a line (in extract) or disc (in zygotes) of antiparallel microtubule bundles coated with cytokinesis midzone proteins. Interaction zones block interpenetration of microtubules from the two asters, and signal to the cortex to induce cleavage furrows. Their reconstitution in extract allows dissection of the biophysics of spatially regulated cytokinesis signaling.
Microfluidic devices for small-angle neutron scattering
Authors: Lopez Carlos G. , Watanabe Takaichi , Adamo Marco , Martel Anne , Porcar Lionel , Cabral João T.
Published: June 2018

A comparative examination is presented of materials and approaches for the fabrication of microfluidic devices for small-angle neutron scattering (SANS). Representative inorganic glasses, metals, and polymer materials and devices are evaluated under typical SANS configurations. Performance criteria include neutron absorption, scattering background and activation, as well as spatial resolution, chemical compatibility and pressure resistance, and also cost, durability and manufacturability. Closed-face polymer photolithography between boron-free glass (or quartz) plates emerges as an attractive approach for rapidly prototyped microfluidic SANS devices, with transmissions up to ∼98% and background similar to a standard liquid cell (I ≃ 10−3 cm−1). For applications requiring higher durability and/or chemical, thermal and pressure resistance, sintered or etched boron-free glass and silicon devices offer superior performance, at the expense of various fabrication requirements, and are increasingly available commercially.
The Spectroscopy Village at Diamond Light Source
Authors: Diaz-Moreno Sofia , Amboage Monica , Basham Mark , Boada Roberto , Bricknell Nicolas E. , Cibin Giannantonio , Cobb Thomas M. , Filik Jacob , Freeman Adam , Geraki Kalotina , Gianolio Diego , Hayama Shusaku , Ignatyev Konstantin , Keenan Luke , Mikulska Iuliia , Mosselmans J. Frederick W. , Mudd James J. , Parry Stephen A.
Published: June 2018

This manuscript presents the current status and technical details of the Spectroscopy Village at Diamond Light Source. The Village is formed of four beamlines: I18, B18, I20-Scanning and I20-EDE. The village provides the UK community with local access to a hard X-ray microprobe, a quick-scanning multi-purpose XAS beamline, a high-intensity beamline for X-ray absorption spectroscopy of dilute samples and X-ray emission spectroscopy, and an energy-dispersive extended X-ray absorption fine-structure beamline. The optics of B18, I20-scanning and I20-EDE are detailed; moreover, recent developments on the four beamlines, including new detector hardware and changes in acquisition software, are described.
Large-area single-photon-counting CdTe detector for synchrotron radiation computed tomography: a dedicated pre-processing procedure
Authors: Brombal Luca , Donato Sandro , Brun Francesco , Delogu Pasquale , Fanti Viviana , Oliva Piernicola , Rigon Luigi , Di Trapani Vittorio , Longo Renata , Golosio Bruno
Published: June 2018

Large-area CdTe single-photon-counting detectors are becoming more and more attractive in view of low-dose imaging applications due to their high efficiency, low intrinsic noise and absence of a scintillating screen which affects spatial resolution. At present, however, since the dimensions of a single sensor are small (typically a few cm2), multi-module architectures are needed to obtain a large field of view. This requires coping with inter-module gaps and with close-to-edge pixels, which generally show a non-optimal behavior. Moreover, high-Z detectors often show gain variations in time due to charge trapping: this effect is detrimental especially in computed tomography (CT) applications where a single tomographic image requires hundreds of projections continuously acquired in several seconds. This work has been carried out at the SYRMEP beamline of the Elettra synchrotron radiation facility (Trieste, Italy), in the framework of the SYRMA-3D project, which aims to perform the world's first breast-CT clinical study with synchrotron radiation. An ad hoc data pre-processing procedure has been developed for the PIXIRAD-8 CdTe single-photon-counting detector, comprising an array of eight 30.7 mm × 24.8 mm modules tiling a 246 mm × 25 mm sensitive area, which covers the full synchrotron radiation beam. The procedure consists of five building blocks, namely dynamic flat-fielding, gap seaming, dynamic ring removal, projection despeckling and around-gap equalization. Each block is discussed and compared, when existing, with conventional approaches. The effectiveness of the pre-processing is demonstrated for phase-contrast CT images of a human breast specimen. The dynamic nature of the proposed procedure, which provides corrections dependent upon the projection index, allows the effective removal of time-dependent artifacts, preserving the main image features including phase effects.
Monoclinic distortion, polarization rotation and piezoelectricity in the ferroelectric Na0.5Bi0.5TiO3
Authors: Choe Hyeokmin , Bieker Johannes , Zhang Nan , Glazer Anthony Michael , Thomas Pam A. , Gorfman Semën
Published: June 2018

The relationship between crystal structure and physical properties in the ferroelectric Na0.5Bi0.5TiO3(NBT) has been of interest for the last two decades. Originally, the average structure was held to be of rhombohedral (R3c) symmetry with a fixed polarization direction. This has undergone a series of revisions, however, based on high-resolution X-ray diffraction, total neutron scattering, and optical and electron microscopy. The recent experimental findings suggest that the true average symmetry is monoclinic (space groupCc), which allows for a rotatable spontaneous polarization. Neither polarization rotation nor its potentially important real role in enhanced piezoelectricity is well understood. The present work describes anin situinvestigation of the average monoclinic distortion in NBT by time-resolved single-crystal X-ray diffraction under external electric fields. The study presents a high-resolution inspection of the characteristic diffraction features of the monoclinic distortion – splitting of specific Bragg reflections – and their changes under a cyclic electric field. The results favour a model in which there is direct coupling between the shear monoclinic strain and the polarization rotation. This suggests that the angle of polarization rotation under a sub-coercive electric field could be 30° or more.
Construction of personal knowledge maps for a peer-to-peer information-sharing environment
Authors: Qin Chunxiu , Zhao Pengwei , Mou Jian , Zhang Jin
Published: June 2018

Purpose

Browsing knowledge documents in a peer-to-peer (P2P) environment is difficult because knowledge documents in such an environment are large in quantity and distributed over different peers who organize the documents according to their own views. This paper aims to propose a method for constructing a personal knowledge map for a peer to facilitate knowledge browsing and alleviate information overload in P2P environments.

Design/methodology/approach

The research presents a method for constructing a personal knowledge map. The method adopts an ontology-concept-tree-based classification algorithm to recognize a peer’s personal knowledge structure and construct a personal knowledge map, and uses a self-organizing map algorithm to cluster and visualize the knowledge documents. The correctness of the created knowledge map is evaluated with a collection of abstracts of academic papers.

Findings

The method for constructing a personal knowledge map is the main finding of this research. The evaluation shows that the created knowledge map is good in quality.

Research limitations/implications

The proposed method provides a way for P2P platforms to understand their users’ knowledge background, as well as to improve the P2P platform environment. However, the proposed method will not help a peer when he has nothing in his individual knowledge document repository (i.e. the “cold start” problem). The method also requires a relatively good ontology base for a P2P document sharing system to use the method effectively.

Originality/value

It is novel that the proposed method organizes the knowledge documents related to a peer’s knowledge background into a personal knowledge map. Moreover, the created knowledge map combines the advantages of a hierarchical display and a map display. It has values for a distributed P2P environment to facilitate users’ knowledge browsing and to alleviate information overload.
Persuading end users to act cautiously online: a fear appeals study on phishing
Authors: Jansen Jurjen , van Schaik Paul
Published: June 2018

Purpose

The purpose of this paper is to test the protection motivation theory (PMT) in the context of fear appeal interventions to reduce the threat of phishing attacks. In addition, it was tested to what extent the model relations are equivalent across fear appeal conditions and across time.

Design/methodology/approach

A pre-test post-test design was used. In the pre-test, 1,201 internet users filled out an online survey and were presented with one of three fear appeal conditions: strong fear appeal, weak fear appeal and control condition. Arguments regarding vulnerability of phishing attacks and response efficacy of vigilant online information-sharing behaviour were manipulated in the fear appeals. In the post-test, data were collected from 786 internet users and analysed with partial least squares path modelling.

Findings

The study found that PMT model relations hold in the domain of phishing. Self-efficacy and fear were the most important predictors of protection motivation. In general, the model results were equivalent across conditions and across time.

Practical Implications

It is important to consider online information-sharing behaviour because it facilitates the occurrence and success of phishing attacks. The results give practitioners more insight into important factors to address in the design of preventative measures to reduce the success of phishing attacks. Future research is needed to test how fear appeals work in real-world settings and over longer periods.

Originality/value

This paper is a substantial adaptation of a previous conference paper (Jansen and Van Schaik, 2017a, b).
Enhancing quality of work life in India: the role of workplace flexibility
Authors: Rastogi Mansi , Rangnekar Santosh , Rastogi Renu
Published: June 2018

Purpose

It has been claimed that workplace flexibility is beneficial for employees as well as employers. However, not many studies have attempted to examine the impact of workplace flexibility on employees. The purpose of this paper is to examine the impact of flexibility dimensions on quality of work life (QWL) of employees.

Design/methodology/approach

Data were collected from a sample of 380 middle-level employees from service and manufacturing sector in India. Analyses were carried out using multiple regressions with the help of SPSS AMOS 21.

Findings

Flexibility in time and place as well as operations has a significant impact on QWL of middle-level employees. Additionally, flexibility in time and place is indicated to be a strong predictor for enhanced QWL particularly for married female employees as compared to their male counterparts. The type of organisation and sector also influences QWL of middle-level employees.

Research limitations/implications

This study has projected theoretical justification indicating how workplace flexibility satisfies needs of middle-level employees and promotes their QWL. It contributes to positive psychology literature by illustrating empirical evidence supporting the crucial role of flexibility at workplace in enhancing QWL of employees in India.

Practical implications

The findings may be valuable in all kinds of organisational settings when reviewing and proposing motivational employee well-being related policies. The empirical findings may have practical implications when it comes to designing jobs for enhanced work engagement.

Originality/value

The variables examined in this study reflect an understanding about how support mechanism at workplace creates a positive effect in employees’ well-being in unique cultural settings of India. Thus, this study is a significant contribution to the well-being literature in India.
Lecturers’ perceptions on factors influencing the implementation of bilingual instruction in Indonesian universities
Authors: Abduh Amirullah
Published: June 2018

Purpose

The purpose of this paper is to explore lecturers’ perceptions on factors that affect the implementation of bilingual instruction (BI) policy in Indonesian higher education.

Design/methodology/approach

This qualitative study used 15 lecturers who taught in BI programs in three Indonesian universities. The data were gained through semi-structured interviews. The semi-structured interview data were analyzed via thematic approach.

Findings

The findings of the study suggest a number of factors influencing the implementation of BI, including the support from lecturers, leadership, and government. The availability of adapted curriculum and systematic assessment also influences the successful implementation of BI in Indonesian tertiary education.

Practical implications

The findings of this study have implications for the success of similar programs and the ways to gain understanding of BI within higher education contexts.

Originality/value

BI research is not new; however, little information is related to BI in Indonesia. This work contributes to a growing body of literature that explore BI and education factors within higher education setting. The significance of this study is to raise greater understanding of several important factors that influence the implementation of BI policy within university settings.
Influence of e-WOM engagement on consumer purchase intention in social commerce
Authors: Yusuf Ali Sahabi , Che Hussin Ab Razak , Busalim Abdelsalam H.
Published: June 2018

Purpose

As a business paradigm, social commerce (s-commerce) has brought about a new stage of innovation, and by extension, has transmuted the power from seller to buyer. S-commerce is a combination a commercial and social activities in which individuals may spread word of mouth (WOM) about their shopping experiences and knowledge and provide information about product and services to their to their friends. This kind of social interactions among individuals has increased the potentials of eWOM communication. Given such a backdrop, this paper aims to look into the influence of eWOM engagement on consumers’ purchase intention in s-commerce, which may complement the current effort of the research community in this area.

Design/methodology/approach

This study used elaboration likelihood model, theory of reasoned action and social support theory to investigate the influence of eWOM engagement on consumers’ purchase intention in s-commerce. The study used 218 respondents to evaluate the proposed model using SmartPLS.

Findings

The empirical results indicate that information characteristics, consumer behavior and technological factors exert a positive influence on consumer purchase intentions. All hypotheses between attitude toward eWOM, information credibility, innovativeness, website quality and eWOM engagement are significant. Also, eWOM engagement has a significant positive influence on consumer purchase intention. However, information quality and social support does not have any significant relationship with eWOM engagement.

Research limitations/implications

This study seeks to address the dearth of research in the field of s-commerce, especially as it relates to eWOM. The study proposes a new model and empirically validates the hypothesized relationships. This research can serve as a stepping stone for future research in this field.

Practical implications

This study is one of the early studies focusing on the influence of eWOM engagement, especially in s-commerce. The study offers comprehensive and empirically validated factors pertaining to eWOM engagement in s-commerce. The results of this study are also important to practitioners and online companies’ managers. The study’s model has demonstrated the contextualization of what makes customers engage in eWOM and its influence in s-commerce. The study will also offer insights for firms on how to encourage eWOM engagement among customers.

Originality/value

A new eWOM engagement model in s-commerce is proposed with consideration on information characteristics, consumer behavior, technological and social factors. The model is validated afterwards.
The institutional role of business school accreditation agencies: a systematic literature review
Authors: Teixeira Gislaine Cristina dos Santos , Maccari Emerson Antonio
Published: June 2018

Purpose

Accreditation is a growing phenomenon and has begun to permeate scientific studies, most of which are quantitative, since they focus on the process of accreditation and its positive or negative effects. Only a few studies have analyzed this phenomenon from the perspective of institutional theory. As there is no consensus regarding the performance of accreditation agencies, the purpose of this paper is to identify their institutional role in the global orientation of the organizational practices, values and decisions of business schools (BS).

Design/methodology/approach

A systematic literature review enabled us to identify scientific publications since 2002 that have used institutional theory when discussing BS accreditation agencies. An in-depth reading of these articles led us to identify the most frequent, similar and contrasting perspectives. Seven aspects were analyzed in each article: theme, research assumption, theoretical basis, method, research context, result and suggestions for future studies.

Findings

The findings suggest a certain duality in the role of these agencies. If, on the one hand, they are responsible for providing a quality seal, on the other hand, they promote legitimacy in the field by institutionalizing international rules.

Originality/value

By investigating the performance of these agencies as global institutional bodies, the authors extrapolated the traditional discussion on the dynamic of interaction between local actors who both influence the field and are influenced by it, a recurring theme in institutional theory.