bluuebunny/crossref_metadata_2025 huggingface dataset:
Safety and Efficacy of Recombinant Human Bone Morphogenetic Protein-2 (rhBMP-2) in Craniofacial Surgery
Authors: Ramly Elie P. , Alfonso Allyson R. , Kantar Rami S. , Wang Maxime M. , Siso J. Rodrigo Diaz , Ibrahim Amel , Coelho Paulo G. , Flores Roberto L.
Published: August 2019

Introduction:

Recombinant human bone morphogenetic protein-2 (rhBMP-2) is one of the most commonly used osteogenic agents in the craniofacial skeleton. This study reviews the safety and efficacy of rhBMP-2 as applied to craniofacial reconstruction and assesses the level of scientific evidence currently available.

Methods:

An extensive literature search was conducted. Randomized controlled trials (RCTs), case series and reports in the English language as well as Food and Drug Administration reports were reviewed. Studies were graded using the Oxford Center for Evidence-Based Medicine Levels of Evidence Scale. Data heterogeneity precluded quantitative analysis.

Results:

Seventeen RCTs (Levels of evidence: Ib-IIb) were identified evaluating the use of rhBMP-2 in maxillary sinus, alveolar ridge, alveolar cleft, or cranial defect reconstruction (sample size: 7–160; age: 8–75 years). Study designs varied in rigor, with follow-up ranging 3–36 months, and outcome assessment relying on clinical exam, radiology, and/or histology. There was wide variation in rhBMP-2 concentrations, carriers, and controls. Most studies evaluating rhBMP-2 for cranial defect closure, mandibular reconstruction, or distraction osteogenesis consisted of retrospective cohorts and case reports. The evidence fails to support RhBMP-2 use in maxillary sinus wall augmentation, calvarial reconstruction, mandibular reconstruction, or distraction osteogenesis. RhBMP-2 may be effective in alveolar reconstruction in adults, but is associated with increased postoperative edema.

Conclusions:

A risk–benefit ratio favoring rhBMP-2 over alternative substitutes remains to be demonstrated for most applications in plastic and reconstructive surgery. Long-term data on craniofacial growth is lacking, and using rhBMP-2 in patients younger than 18 years remains off-label.
A Deep Learning Approach in Rebubbling After Descemet's Membrane Endothelial Keratoplasty
Authors: Hayashi Takahiko , Tabuchi Hitoshi , Masumoto Hiroki , Morita Shoji , Oyakawa Itaru , Inoda Satoru , Kato Naoko , Takahashi Hidenori
Published: August 2019

Purpose:

To evaluate the efficacy of deep learning in judging the need for rebubbling after Descemet's endothelial membrane keratoplasty (DMEK).

Methods:

This retrospective study included eyes that underwent rebubbling after DMEK (rebubbling group: RB group) and the same number of eyes that did not require rebubbling (non-RB group), based on medical records. To classify the RB group, randomly selected images from anterior segment optical coherence tomography at postoperative day 5 were evaluated by corneal specialists. The criterion for rebubbling was the condition where graft detachment reached the central 4.0-mm pupil area. We trained nine types of deep neural network structures (VGG16, VGG19, ResNet50, InceptionV3, InceptionResNetV2, Xception, DenseNet121, DenseNet169, and DenseNet201) and built nine models. Using each model, we tested the validation data and evaluated the model.

Results:

This study included 496 images (31 eyes from 24 patients) in the RB group and 496 images (31 eyes from 29 patients) in the non-RB group. Because 16 picture images were obtained from the same point of each eye, a total of 992 images were obtained. The VGG19 model was found to have the highest area under the receiver operating characteristic curve (AUC) of all models. The AUC, sensitivity, and specificity of the VGG19 model were 0.964, 0.967, and 0.915, respectively, whereas those of the best ensemble model were 0.956, 0.913, and 0.921, respectively.

Conclusions:

This automated system that enables the physician to be aware of the requirement of RB might be clinically useful.
A Qualitative Review of Neoadjuvant Chemotherapy in Resectable Pancreatic Adenocarcinoma
Authors: Blair Alex B. , Sorber Rebecca , Rozich Noah S. , Burkhart Richard A.
Published: August 2019

The aim of this study was to evaluate outcomes of patients with resectable pancreatic adenocarcinoma (PDAC) who underwent neoadjuvant chemotherapy. The MEDLINE and PubMed databases were searched to identify relevant original articles investigating neoadjuvant therapy in resectable PDAC. Qualitative analyses were performed to investigate patient selection, disease stage, impact on perioperative outcomes, and cost-effectiveness. Forty-three studies met inclusion criteria for this review. Neoadjuvant chemotherapy for upfront resectable PDAC is cost-effective, safe, may result in lower stage disease and has potential survival advantages. With proper patient selection, neoadjuvant chemotherapy is an appropriate approach for upfront resectable PDAC. Nevertheless, the risk for disease progression and losing a curative surgical window highlights the need for appropriate patient identification, further discovery of superior biomarkers or molecular profiles representative of positive treatment response, and additional prospective comparative study.
Facilitating Timely Advance Care Planning
Authors: Crosby Erin M. , Gutierrez Karen M.
Published: August 2019

This quality improvement project utilized a risk stratification process and an advance care planning (ACP) tool to identify patients at high risk of death and prompt ACP discussions and documentation of health care preferences in the electronic health record. Inherent uncertainty in heart failure (HF) prognostication and provider time constraints impede initiation of timely ACP discussions. In an effort to mitigate these obstacles, the Seattle Heart Failure Model was utilized to calculate mortality risk for 195 patients in an ambulatory HF clinic. Next, a HF-specific ACP tool, developed for this project, was used to prompt and guide ACP discussions with patients determined to have a prognosis of life expectancy of 3 years or less. The project yielded a 35% completion of ACP tools over 3 months, with 100% of these entered into the electronic health record. Postimplementation surveys suggest clinic staff believe a comprehensive and systematic approach to ACP services facilitates timely ACP discussions and decision making in the outpatient setting.
Brief Report: Diagnostic Accuracy of Oral Mucosal Transudate Tests Compared with Blood-Based Rapid Tests for HIV Among Children Aged 18 Months to 18 Years in Kenya and Zimbabwe
Authors: Dziva Chikwari Chido , Njuguna Irene N. , Neary Jillian , Rainer Crissi , Chihota Belinda , Slyker Jennifer A. , Katz David A. , Wamalwa Dalton C. , Oyiengo Laura , Bandason Tsitsi , McHugh Grace , Dauya Ethel , Mujuru Hilda , Stewart Kearsley A. , John-Stewart Grace C. , Ferrand Rashida A. , Wagner Anjuli D.
Published: August 2019

Background:

Gaps persist in HIV testing for children who were not tested in prevention of mother-to-child HIV transmission programs. Oral mucosal transudate (OMT) rapid HIV tests have been shown to be highly sensitive in adults, but their performance has not been established in children.

Methods:

Antiretroviral therapy-naive children aged 18 months to 18 years in Kenya and Zimbabwe were tested for HIV using rapid OraQuick ADVANCE Rapid HIV-1/2 Antibody test on oral fluids (OMT) and blood-based rapid diagnostic testing (BBT). BBT followed Kenyan and Zimbabwean national algorithms. Sensitivity and specificity were calculated using the national algorithms as the reference standard.

Results:

A total of 1776 children were enrolled; median age was 7.3 years (interquartile range: 4.7–11.6). Among 71 children positive by BBT, all 71 were positive by OMT (sensitivity: 100% [97.5% confidence interval (CI): 94.9% to 100%]). Among the 1705 children negative by BBT, 1703 were negative by OMT (specificity: 99.9% [95% CI: 99.6% to 100.0%]). Due to discrepant BBT and OMT results, 2 children who initially tested BBT-negative and OMT-positive were subsequently confirmed positive within 1 week by further tests. Excluding these 2 children, the sensitivity and specificity of OMT compared with those of BBT were each 100% (97.5% CI: 94.9% to 100% and 99.8% to 100%, respectively).

Conclusions:

Compared to national algorithms, OMT did not miss any HIV-positive children. These data suggest that OMTs are valid in this age range. Future research should explore the acceptability and uptake of OMT by caregivers and health workers to increase pediatric HIV testing coverage.
Long-term culture of human lung adenocarcinoma A549 cells enhances the replication of human influenza A viruses
Authors: Ujie Michiko , Takada Kosuke , Kiso Maki , Sakai-Tagawa Yuko , Ito Mutsumi , Nakamura Kazuya , Watanabe Shinji , Imai Masaki , Kawaoka Yoshihiro
Published: August 2019

Long-term culture of the human lung adenocarcinoma cell line A549 promotes the differentiation of these cells toward an alveolar type II cell phenotype. Here, we evaluated the susceptibility of long-term cultured A549 cells to human influenza viruses. A549 cells were cultured continuously for 25 days (D25-A549) or 1 day (D1-A549) in Ham’s F12K medium. Six human influenza A viruses grew much faster in D25-A549 cells than in D1-A549 cells; however, two influenza B viruses replicated poorly in both cell types. Two avian influenza viruses replicated efficiently in both cell types, with similar titres. Expression levels of human virus receptors were higher in D25-A549 cells than in D1-A549 cells. D25-A549 cells thus more efficiently support the replication of human influenza A viruses compared with D1-A549 cells. Our data suggest that long-term cultured A549 cells will be useful for influenza A virus research.
Raising animals without antibiotics: producer and veterinarian experiences and opinions
Authors: Singer Randall S. , Porter Leah J. , Thomson Daniel U. , Gage Mallory , Beaudoin Amanda , Wishnie Jennifer K.
Published: August 2019

Ensuring the safety, health, and overall well-being of animals raised for food is both an ethical obligation and a critical component of providing safe food products. The use of antibiotics for maintaining animal health has come under scrutiny in recent years due to the rise of antibiotic resistance globally. Some U.S. producers, especially in the poultry industry, have responded by eliminating their antibiotic use. The number of animals raised without antibiotics (RWA) is growing in the U.S., but there are concerns that RWA practices might negatively impact animal health and welfare. Therefore, the objective of this study was to survey U.S. veterinarians and producers about their experiences and opinions regarding RWA production. Veterinarians, farmers, ranchers, producers, and other stakeholders involved in raising broilers, turkeys, swine, beef cattle or dairy cattle were surveyed. Of the 565 completed responses received, 442 self-reported as practicing veterinarians or producers. Just over half of respondents reported having past or current experience with RWA programs. The main indicated reasons for raising animals without antibiotics were market driven; switching to RWA production was less commonly made for health-related reasons, such as to reduce antibiotic resistance or to improve animal health and welfare. Although respondents felt that RWA production has negative impacts on animal health and welfare, they overwhelmingly (>70%) indicated that the customer (retailer/restaurant/food service) believes that animal and health welfare will be significantly improved. Veterinarians and producers indicated that RWA programs will increase production costs with questionable effect on meat, egg or dairy consumer demand. Many respondents felt that there are times when the RWA label takes priority over animal health and welfare. Respondents generally felt that there was a need for increased auditing/assessment of animal health and welfare in RWA systems.
Horizontal ‘gene drives’ harness indigenous bacteria for bioremediation
Authors: French Katherine E. , Zhou Zhongrui , Terry Norman
Published: August 2019

Engineering bacteria to clean-up oil spills is rapidly advancing but faces regulatory hurdles and environmental concerns. Here, we develop a new technology to harness indigenous soil microbial communities for bioremediation by flooding local populations with catabolic genes for petroleum hydrocarbon degradation. Overexpressing three enzymes (almA, xylE, p450cam) inE.coliled to degradation rates of 60-99% of target hydrocarbon substrates. Mating experiments, fluorescence microscopy and TEM revealed indigenous bacteria could obtain these vectors fromE.colithrough several mechanisms of horizontal gene transfer (HGT), including conjugation and cytoplasmic exchange through nanotubes. Inoculating petroleum-polluted sediments withE.colicarrying the vector pSF-OXB15-p450camfusion showed that theE.colidie after five days but a variety of bacteria received and carried the vector for over 60 days after inoculation. Within 60 days, the total petroleum hydrocarbon content of the polluted soil was reduced by 46%. Pilot experiments show that vectors only persist in indigenous populations when “useful,” disappearing when this carbon source is removed. This approach to remediation could prime indigenous bacteria for degrading pollutants while providing minimal ecosystem disturbance.
AANAT1 functions in astrocytes to regulate sleep homeostasis
Authors: Davla Sejal , Artiushin Gregory , Chitsaz Daryan , Li Sally , Sehgal Amita , van Meyel Donald J.
Published: August 2019

Characteristic features of sleep are conserved among species [1], and from humans to insects sleep is influenced by neural circuits involving monoamines such as serotonin and dopamine [2]. Glial cells have been increasingly implicated in mechanisms of baseline and homeostatic sleep regulation in mammals and flies [3–11], but it remains unknown whether and how glia might influence monoaminergic control of sleep. Sleep is regulated by circadian rhythms and a homeostatic drive to compensate for prolonged wakefulness, and growing evidence suggests that neural mechanisms controlling homeostatic sleep can be discriminated from those controlling baseline sleep [12–15]. In Drosophila, mutants of arylalkylamine N-acetyltransferase 1 (AANAT1lo) have normal baseline amounts of sleep and motor activity, but increased rebound sleep following deprivation [16]. AANAT1 can acetylate and inactivate monoamines in vitro [17], but the role of AANAT1 in vivo remains poorly understood. We find AANAT1 to be expressed in astrocytes and subsets of neurons in the adult Drosophila brain, with levels in astrocytes declining markedly overnight. In sleep-deprived AANAT1 mutant flies, heightened rebound sleep is accompanied by increased serotonin and dopamine levels in the brain. In neurons, AANAT1 functions to limit the quantity and consolidation of nighttime sleep, but in astrocytes AANAT1 constrains the amount of rebound sleep that flies take in response to sleep deprivation. These findings distinguish sleep-control functions of AANAT1 in neurons and astrocytes, and identify a critical role for astrocytes in the regulation of monoamine bioavailability and calibration of the response to sleep need.

Highlights

The monoamine catabolic enzyme arylalkylamine N-acetyltransferase 1 (AANAT1) is expressed by astrocytes and subsets of serotonergic, glutamatergic, GABAergic and cholinergic neurons in the adult brain of Drosophila.

AANAT1 limits accumulation of serotonin and dopamine in the brain upon sleep deprivation.

Loss of AANAT1 from astrocytes, but not from neurons, causes flies to increase their daytime rebound sleep in response to overnight sleep deprivation.
mTORC1 signaling is not essential for the maintenance of muscle mass and function in adult sedentary mice
Authors: Ham Alexander S. , Chojnowska Kathrin , Tintignac Lionel A. , Lin Shuo , Schmidt Alexander , Ham Daniel J. , Sinnreich Michael , Rüegg Markus A.
Published: August 2019

Background

The balance between protein synthesis and degradation (proteostasis) is a determining factor for muscle size and function. Signaling via the mammalian target of rapamycin complex 1 (mTORC1) regulates proteostasis in skeletal muscle by affecting protein synthesis and autophagosomal protein degradation. Indeed, genetic inactivation of mTORC1 in developing and growing muscle causes atrophy resulting in a lethal myopathy. However, systemic dampening of mTORC1 signaling by its allosteric inhibitor rapamycin is beneficial at the organismal level and increases lifespan. Whether the beneficial effect of rapamycin comes at the expense of muscle mass and function is yet to be established.

Methods

We conditionally ablated the gene coding for the mTORC1-essential component raptor in muscle fibers of adult mice (iRAmKO). We performed detailed phenotypic and biochemical analyses of iRAmKO mice and compared them with RAmKO mice, which lack raptor in developing muscle fibers. We also used polysome profiling and proteomics to assess protein translation and associated signaling in skeletal muscle of iRAmKO mice.

Results

Analysis at different time points reveal that, as in RAmKO mice, the proportion of oxidative fibers decreases, but slow-type fibers increase in iRAmKO mice. Nevertheless, no significant decrease in body and muscle mass, or muscle fiber area was detected up to 5 months post-raptor depletion. Similarly, ex vivo muscle force was not significantly reduced in iRAmKO mice. Despite stable muscle size and function, inducible raptor depletion significantly reduced the expression of key components of the translation machinery and overall translation rates.

Conclusions

Raptor depletion and hence complete inhibition of mTORC1 signaling in fully-grown muscle leads to metabolic and morphological changes without inducing muscle atrophy even after 5 months. Together, our data indicate that maintenance of muscle size does not require mTORC1 signaling, suggesting that rapamycin treatment is unlikely to negatively affect muscle mass and function.
Theta Phase-Dependent Modulation of Perception by Concurrent tACS and Periodic Visual Stimulation
Authors: Somer Elif , Allen John , Brooks Joseph , Buttrill Vaughan , Javadi Amir-Homayoun
Published: August 2019

Background

Sensory perception can be modulated by the phase of neural oscillations, especially in the theta and alpha ranges. Oscillatory activity in the visual cortex can be entrained by transcranial alternating current stimulation (tACS) as well as periodic visual stimulation (i.e., flicker). Combined tACS and visual flicker stimulation modulates blood-oxygen-level-dependent (BOLD) responses and concurrent 4 Hz auditory click-trains and tACS modulates auditory perception in a phase-dependent way.

Objective

In the present study, we investigated if phase synchrony between concurrent tACS and periodic visual stimulation (i.e., flicker) can modulate performance on a visual matching task.

Methods

Participants completed a visual matching task on a flickering visual stimulus while receiving either in-phase (0 degree) or asynchronous (180, 90, or 270 degrees) tACS at alpha or theta frequency. Stimulation was applied over either occipital cortex or dorsolateral prefrontal cortex (DLPFC).

Results

Visual performance was significantly better during theta frequency tACS over the visual cortex when it was in-phase (0 degree) with visual stimulus flicker, compared to anti-phase (180 degree). This effect did not appear with alpha frequency flicker or with DLPFC stimulation. Furthermore, a control sham group showed no effect. There were no significant performance differences amongst the asynchronous (180, 90, and 270 degrees) phase conditions.

Conclusion

Extending previous studies on visual and auditory perception, our results support a crucial role of oscillatory phase in sensory perception and demonstrate a behaviourally relevant combination of visual flicker and tACS. The spatial and frequency specificity of our results have implications for research on the functional organisation of perception.
Two real use cases of FAIR maturity indicators in the life sciences
Authors: Bonaretti Serena , Willighagen Egon
Published: August 2019

Data sharing and reuse are crucial to enhance scientific progress and maximize return of investments in science. Although attitudes are increasingly favorable, data reuse remains difficult for lack of infrastructures, standards, and policies. The FAIR (findable, accessible, interoperable, reusable) principles aim to provide recommendations to increase data reuse. Because of the broad interpretation of the FAIR principles, maturity indicators are necessary to determine FAIRness of a dataset. In this work, we propose a reproducible computational workflow to assess data FAIRness in the life sciences. Our implementation follows principles and guidelines recommended by the maturity indicator authoring group and integrates concepts from the literature. In addition, we propose a FAIR balloon plot to summarize and compare dataset FAIRness. We evaluated our method on two real use cases where researchers looked for datasets to answer their scientific questions. We retrieved information from repositories (ArrayExpress and Gene Expression Omnibus), a registry of repositories (re3data.org), and a searchable resource (Google Dataset Search) via application program interface (API) wherever possible. With our analysis, we found that the two datasets met the majority of the criteria defined by the maturity indicators, and we showed areas where improvements can easily be reached. We suggest that use of standard schema for metadata and presence of specific attributes in registries of repositories could increase FAIRness of datasets.
Cortical Overgrowth in a Preclinical Forebrain Organoid Model of CNTNAP2-Associated Autism Spectrum Disorder
Authors: de Jong Job O. , Llapashtica Ceyda , Strauss Kevin , Provenzano Frank , Sun Yan , Cortese Giuseppe P. , Brigatti Karlla W. , Corneo Barbara , Migliori Bianca , Kushner Steven A. , Kellendonk Christoph , Javitch Jonathan A. , Xu Bin , Markx Sander
Published: August 2019

Autism spectrum disorder (ASD) represents a major public health burden but translating promising treatment findings from preclinical non-human models of ASD to the clinic has remained challenging. The recent development of forebrain organoids generated from human induced pluripotent stem cells (hiPSCs) derived from subjects with brain disorders is a promising method to study human-specific neurobiology, and may facilitate the development of novel therapeutics.

In this study, we utilized forebrain organoids generated from hiPSCs derived from patients from the Old Order Amish community with a rare syndromic form of ASD, carrying a homozygous c.3709DelG mutation in CNTNAP2 and healthy controls to investigate the effects of this mutation on cortical embryonic development.

Patients carrying the c.3709DelG mutation in CNTNAP2 present with an increased head circumference and brain MRI reveals an increase in gray matter volume. Patient-derived organoids displayed an increase in total volume that was driven by an increased proliferation in neural progenitor cells, leading to an increase in the generation of cortical neuronal and non-neuronal cell types. The observed phenotypes were rescued after correction of the pathogenic mutation using CRISPR-Cas9. RNA sequencing revealed 339 genes differentially expressed between patient- and control-derived organoids of which a subset are implicated in cell proliferation and neurogenesis. Notably, these differentially expressed genes included previously identified ASD-associated genes and are enriched for genes in ASD-associated weighted gene co-expression networks.

This work provides a critical step towards understanding the role of CNTNAP2 in human cortical development and has important mechanistic implications for ASD associated with brain overgrowth. This CNTNAP2 organoid model provides opportunity for further mechanistic inquiry and development of new therapeutic strategies for ASD.
Association of extent of cannabis use and psychotic like intoxication experiences in a multi-national sample of First Episode Psychosis patients and controls
Authors: Sami Musa , Quattrone Diego , Ferraro Laura , Tripoli Giada , Cascia Erika La , Gayer-Anderson Charlotte , Selten Jean-Paul , Arango Celso , Bernardo Miguel , Tarricone Ilaria , Tortelli Andrea , Gatto Giusy , del Peschio Simona , Del-Ben Cristina Marta , Rutten Bart P. , Jones Peter B. , van Os Jim , de Haan Lieuwe , Morgan Craig , Lewis Cathryn , Bhattacharyya Sagnik , Freeman Tom P , Lynskey Michael , Murray Robin M. , Forti Marta Di
Published: August 2019

Aims

First Episode Psychosis (FEP) patients who use cannabis experience more frequent psychotic and euphoric intoxication experiences compared to controls. It is not clear whether this is consequent to patients being more vulnerable to the effects of cannabis use or to their heavier pattern of use. We aimed to determine whether extent of use predicted psychotic-like and euphoric intoxication experiences in FEP patients and controls and whether this differs between groups.

Methods

We analysed data on lifetime cannabis using patients (n=655) and controls (n=654) across 15 sites from six countries in the EU-GEI study (2010-2015). We used multiple regression to model predictors of cannabis-induced experiences and to determine if there was an interaction between caseness and extent of use.

Results

Caseness, frequency of cannabis use and money spent on cannabis predicted psychotic-like and euphoric experiences, independent of other experiences (p≤0.001). For psychotic-like experiences there was a significant interaction for caseness x frequency of use (p<0.001) and caseness x money spent on cannabis (p=0.001) such that FEP patients had increased experiences at increased levels of use compared to controls. There was no similar significant interaction for euphoric experiences (p>0.5).

Conclusions and Relevance

FEP patients are particularly sensitive to increased psychotic-like, but not euphoric experiences, at higher frequency and amount of cannabis use compared to controls. This suggests a specific psychotomimetic response in patients related particularly to heavy cannabis use.
Structure ofS. pombetelomerase protein Pof8 C-terminal domain is an xRRM conserved among LARP7 proteins
Authors: Basu Ritwika , Eichhorn Catherine D. , Cheng Ryan , Feigon Juli
Published: August 2019

La related proteins group 7 (LARP7) are a class of RNA chaperones that bind the 3’ends of RNA and are constitutively associated with their specific target RNAs. In metazoa, Larp7 binds to the long non-coding 7SK RNA as a core component of the 7SK RNP, a major regulator of eukaryotic transcription. In ciliates, a LARP7 protein (p65 inTetrahymena) is a core component of telomerase, an essential ribonucleoprotein complex that maintains the DNA length at eukaryotic chromosome ends. p65 is important for the ordered assembly of telomerase RNA (TER) with telomerase reverse transcriptase (TERT). Although a LARP7 as a telomerase holoenzyme component was initially thought to be specific to ciliate telomerases,Schizosaccharomyces pombePof8 was recently identified as a LARP7 protein and a core component of fission yeast telomerase essential for biogenesis. There is also evidence that human Larp7 associates with telomerase. LARP7 proteins have conserved N-terminal La motif and RRM1 (La module) and C-terminal RRM2 with specific RNA substrate recognition attributed to RRM2, first structurally characterized in p65 as an atypical RRM named xRRM. Here we present the X-ray crystal structure and NMR studies ofS. pombePof8 RRM2. Sequence and structure comparison of Pof8 RRM2 to p65 and hLarp7 xRRMs reveals conserved features for RNA binding with the main variability in the length of the non-canonical helix α3. This study shows that Pof8 has conserved xRRM features, providing insight into TER recognition and the defining characteristics of the xRRM.

Highlights

The structure of theS. pombeLARP7 Pof8 C-terminal domain is an xRRM.

Ciliates, human, and fission yeast contain LARP7 proteins with xRRMs involved in telomerase biogenesis.

With three examples of xRRM structures, we refine the definition of xRRM.
Supporting evidence for DNA shearing as a mechanism for origin unwinding in eukaryotes
Authors: Langston Lance D. , Georgescu Roxana , O’Donnell Mike E.
Published: August 2019

Our earlier study demonstrated that head-to-head CMGs that encircle duplex DNA and track inward at origins, melt double-strand (ds) DNA while encircling the duplex by pulling on opposite strands and shearing DNA apart (Langston and O’Donnell (2019) eLife9, e46515). We show here that increasing the methylphosphonate neutral DNA from 10 nucleotides in the previous report, to 20 nucleotides, reveals that CMG encircling duplex DNA only interacts with the tracking strand compared to the non-tracking strand. This significantly enhances support that CMG tracks on duplex DNA by binding only one strand. Furthermore, EMSA assays using AMPPNP to load CMG onto DNA shows a stoichiometry of only 2 CMGs on an origin mimic DNA, containing a 150 bp duplex with two 3 prime single-strand (ss) tails, one on each end, enabling assay of dsDNA unwinding by a shearing force produced by only two head-to-head CMGs. The use of non-hydrolysable AMPPNP enabled a preincubation for CMG binding the two 3 prime tailed origin mimic DNA, and gave robust unwinding of dsDNA by head-to-head CMG-Mcm10’s. With this precedent, it is possible to envision that the cell may utilize opposing dsDNA motors to unwind DNA for other types of DNA transactions besides origin unwinding.
Operation of photon diagnostic imagers for beam commissioning at the European XFEL
Authors: Koch Andreas , Risch Johannes , Freund Wolfgang , Maltezopoulos Theophilos , Planas Marc , Grünert Jan
Published: August 2019

X-ray photon beam diagnostic imagers are located at 24 positions in the European XFEL beam transport system to characterize the X-ray beam properties, and to give feedback for tuning and optimization of the electron acceleration and orbit, the undulators, and the X-ray optics. One year of commissioning allowed experience to be gained with these imagers, which will be reported here. The sensitive Spontaneous Radiation imager is useful for various investigations in spontaneous radiation mode: for undulator adjustments and for low-signal imaging applications. The high-resolution Free-Electron Laser imager, 10 µm spatial resolution, is extensively used for the monitoring of beam position, spot size and shape, gain curve measurements, and also for beam-intensity monitoring. The wide field-of-view pop-in monitors (up to 200 mm) are regularly used for alignment and tuning of the various X-ray optical components like mirrors, slits and monochromators, and also for on-line beam control of a stable beam position at the instruments. The Exit Slit imager after the soft X-ray monochromator provides spectral information of the beam together with multi-channel plate based single-pulse gating. For particular use cases, these special features of the imagers are described. Some radiation-induced degradation of scintillators took place in this initial commissioning phase, providing useful information for better understanding of damage thresholds. Visible-light radiation in the beam pipe generated by upstream bending magnets caused spurious reflections in the optical system of some of the imagers which can be suppressed by aluminium-coated scintillating screens.
Jitter correction for transmission X-ray microscopy via measurement of geometric moments
Authors: Wang Shengxiang , Liu Jianhong , Li Yinghao , Chen Jian , Guan Yong , Zhu Lei
Published: August 2019

Transmission X-ray microscopes (TXMs) have become one of the most powerful tools for imaging 3D structures of nano-scale samples using the computed tomography (CT) principle. As a major error source, sample jitter caused by mechanical instability of the rotation stage produces shifted 2D projections, from which reconstructed images contain severe motion artifacts. In this paper, a jitter correction algorithm is proposed, that has high accuracy and computational efficiency for TXM experiments with or without nano-particle markers. Geometric moments (GMs) are measured on segmented projections for each angle and fitted to sinusoidal curves in the angular direction. Sample jitter is estimated from the difference between the measured and the fitted GMs for image correction. On a digital phantom, the proposed method removes jitter errors at different noise levels. Physical experiments on chlorella cells show that the proposed GM method achieves better spatial resolution and higher computational efficiency than the re-projection method, a state-of-the-art algorithm using iterative correction. It even outperforms the approach of manual alignment, the current gold standard, on faithfully maintaining fine structures on the CT images. Our method is practically attractive in that it is computationally efficient and lowers experimental costs in current TXM studies without using expensive nano-particles markers.
Galvanic corrosion of electronic material copper coupled silver-coating in electronic systems
Authors: Huang Hualiang , Bu Furong
Published: August 2019

Purpose

The purpose of this study is to provide a theoretical basis for the study of the galvanic corrosion mechanism of copper coupled silver-coating under a thin electrolyte layer in electronic systems.

Design/methodology/approach

Electrochemical measurements and surface characterizations.

Findings

The results indicate that the potential difference between copper and silver electrodes first quickly increases, and then reaches a relatively stable and large value with the extension of the immersion time. With the significant increase in the cathode/anode area ratio in electronic systems, the area ratio effect obviously accelerates the corrosion of copper due to the remarkable promotion of the cathode process. For a large cathode/anode area ratio, the galvanic current density always maintains a large value and exhibits an increasing trend with the extension of the immersion time, which is attributed that the area ratio effect reduces the protection of corrosion products. For the same area of cathode and anode, the galvanic current density always maintains a small value with the extension of the immersion time due to a low galvanic effect and protective corrosion products.

Practical implications

This work provides some information for the establishment of reliably protective measures for electronic systems in service.

Social implications

This work not only provides some information for the establishment of reliably protective measures for electronic systems in service, but also provides a theoretical basis for the selection of metal materials in microelectronic systems.

Originality/value

This work provides not only a theoretical basis for the study of the galvanic corrosion mechanism of Cu/Ag under a thin electrolyte layer, but also provides some information for the establishment of reliably protective measures for electronic systems in service.
The early development of International New Ventures: a multidimensional exploration
Authors: Kirwan Paul , Ratinho Tiago , van der Sijde Peter , Groen Aard J.
Published: August 2019

Purpose

The purpose of this paper is to investigate the early development stages of International New Ventures (INVs). Specifically, the authors explore how INVs acquire and leverage four kinds of capital – strategic, managerial, financial and social – to recognise a foreign opportunity, begin the pre-foreign entry activities, and finally start the INV.

Design/methodology/approach

A stage-based, multidimensional framework was used to investigate how INVs acquire and use the four capitals throughout the internationalisation process. Drawing on four case studies of high-tech INVs, this study tracks their development in three stages: foreign opportunity, pre-foreign operation and post-foreign operation.

Findings

Results indicate INVs build advantages and internationalisation activities occur before formal operations begin. INVs deliberately orchestrate certain kinds of capital contingent to the specific internationalisation stage. Further, the authors find that not all types of capital are equally important throughout the internationalisation process: INVs identify foreign opportunities when endowed with managerial and social capital; INVs source a majority of their managerial and financial capitals externally before internationalising; and INVs only contribute all four capitals simultaneously after internationalising.

Research limitations/implications

Findings contribute to knowledge about the development of INVs pre-internationalisation and pre-founding. The study is limited to a comparative sample of INVs, which impacts the generalisability. However, the findings provide a starting point for investigating similar effects using more representative samples.

Practical implications

Entrepreneurs can be proactive in networking activities to allow them greater opportunity to interact with potential resource providers dependent on the stage of internationalisation.

Originality/value

This study contributes to the international entrepreneurship literature with qualitative evidence of the micro-level processes of internationalisation. Very few studies investigate the early, pre-internationalisation and pre-foundation, development stages of INVs.
Changing facets of higher education in management: a students’ perspective
Authors: Rastogi Shailesh , Sharma Arpita , Panse Chetan Padmakar
Published: August 2019

Purpose

The purpose of this paper is to explore the determinants of effective teaching–learning (ETL) from students’ perspective in B-schools and build a model for the satisfaction of students of B-schools from teaching–learning processes.

Design/methodology/approach

The study employs the descriptive research design, and the cross-sectional data are collected through a structured questionnaire. Out of 320, 302 accurately filled questionnaires were used for the empirical analysis. The data are collected from the masters of business management (MBA) students. An exploratory factor analysis is applied to appraise factors appropriate for ETL. A confirmatory factor analysis is used to establish reliability and validity of the identified factors. Structural equation modeling (SEM) is applied to empirically test the proposed model for ETL.

Findings

The major findings of the current study are as follows: this paper identifies extracurricular activities (ECA), conducive environment (CE) and project work and practical exposure (PWPE) as the determinants of ETL in MBA Programs. These determinants have been identified individually; however, collectively authors do not find any other study that discusses them. This paper explores a suitable and apt model of ETL through the identified determinants of ETL (ECA, CE and PWPE). This is also a contribution of the paper, which has not been observed by the authors, in the literature.

Research limitations/implications

The scope of the research can be enhanced to the all level of management students and colleges of all sorts can be taken.

Practical implications

Findings of this paper are a long-term plan with a futuristic vision. Determinants affecting ETL will help the administrators and faculty members at the MBA programs to realign their focus for the future.

Originality/value

This study determines three determinants (from the students’ points of view) for the effectiveness of the teaching–learning process in the management (MBA) programs. The determinants in this study are ECA, CE and PWPE. SEM is applied to test the model of ETL and to specify these three determinants (constructs). Decision makers for MBA programs can prudently use the model to bring about transformation in teaching–learning processes in business schools.
Heritage: the priceless hostage of accrual accounting
Authors: Anessi-Pessina Eugenio , Caruana Josette , Sicilia Mariafrancesca , Steccolini Ileana
Published: August 2019

Purpose

The purpose of this paper is to examine how the convergence of private and public sector accounting standards is affecting conceptual and practical issues relating to heritage. More specifically, the paper is intended to provide a better understanding of the state of the art in national and international accounting standards on heritage assets, and of the views influencing such standards.

Design/methodology/approach

A qualitative documentary analysis is carried out to explore the variety of existing positions and views on heritage, ranging from the scholarly literature, through potential stakeholders and users, to international and national standard setters.

Findings

The analysis shows that the path of convergence between public and private sector standards and practices is still problematic. After more than two decades of debate around the nature, definition, measurement, and reporting of heritage, these issues are far from settled.

Research limitations/implications

In the light of calls for increased measurement and reporting of public sector “assets”, and specifically for the definition of standards to recognise heritage, the paper suggests the need to strongly reconsider whether the convergence between public and private sector standards is desirable, feasible and effective. As such, the risks of embracing simplified or hybrid forms of accounting and reporting for heritage should be more seriously assessed. While reporting on heritage is important, it is fundamental to keep it distinct from reporting on government’s regular operations, in order to appreciate its specific value, nature and features.

Originality/value

Looking at European national standards for heritage, the IPSASB’s proposals, and the reactions to the latter by relevant stakeholders, the paper provides a pluralistic view on the positions and experiences about heritage, contributing to the debate on the convergence between private and public sector accounting standards.
Differences among baby boomers, Generation X, millennials, and Generation Z wine consumers in Lebanon
Authors: Koksal Mehmet Haluk
Published: August 2019

Purpose

The purpose of the study is to group Lebanese wine consumers based on generational cohorts. It also explores the characteristics of the customers in each group based on wine attributes, information sources, wine consumption, purchase behaviour and socio-economic characteristics.

Design/methodology/approach

The data in the study were collected from the main supermarkets, hypermarkets and special liquor outlets, as well as upscale restaurants serving alcohol in the Lebanese capital, Beirut, through a structured questionnaire. Respondents were intercepted by using convenience sampling. Out of 700 people approached, 444 surveys were collected.

Findings

After splitting consumers into four different generational groups, namely, baby boomers, Generation X, millennials and Generation Z, the study clearly identified the differences between generations regarding wine attributes, information sources, purchasing and consumption and socio-demographic characteristics.

Originality/value

Although there are numerous studies on the investigation of wine consumers in the literature from various countries, this is the first study looking at wine consumers in one of the Middle Eastern countries, Lebanon.
Assessing sustainability performance of high-tech firms through a hybrid approach
Authors: Cui Li , Zhai Mengru , Dai Jing , Liu Yang , Zhang Pan
Published: August 2019

Purpose

In light of the lack of subjective criteria and scientific rationality in current sustainability performance assessment, the purpose of this paper is conducted to improve the sustainability performance assessment of high-tech firms by developing a hybrid approach that integrates quantitative and qualitative research methods.

Design/methodology/approach

This study proposed a hybrid approach that integrates word frequency analysis, cluster analysis, grey theory and the decision-making and trial evaluation laboratory (DEMATEL) method. Specifically, this study identifies useful criteria using quantitative word frequency analysis as well as qualitative literature research. Then, cluster analysis is used to divide these criteria into different categories. Subsequently, this study applies the grey theory associated with the DEMATEL method to assess the sustainability performance of high-tech firms.

Findings

The results reveal that the socio-environment is an important aspect underlying the corporate sustainability performance of high-tech firms. Therefore, high-tech firms should enhance their pollution emission control capabilities and increase investment in energy-conservation and emission-reduction technologies to drive sustainable development. In addition, increasing green product sales revenue and improving the guiding capability of green consumption are core issues that firms must address.

Originality/value

This study assesses the sustainability performance of high-tech firms by applying a hybrid method. This method can be used to construct a framework for scientific sustainability performance assessment and to provide a clear direction for the sustainable development of firms.
A comparative study between a computer-based and a mobile-based assessment
Authors: Nikou Stavros A. , Economides Anastasios A.
Published: August 2019

Purpose

The purpose of this study is to compare the overall usability and user experience of desktop computers and mobile-devices when used in a summative assessment in the context of a higher education course.

Design/methodology/approach

The study follows a between-groups design. The participants were 110 first-year undergraduate students from a European university. Students in the experimental group participated in the assessment using mobile devices, whereas students in the control group participated using desktop computers. After the assessment, students self-reported their experiences with computer-based assessment (CBA) and mobile-based assessment (MBA), respectively. The instruments used were the user experience questionnaire and the system usability scale.

Findings

Attractiveness and novelty were reported significantly higher in the experimental group (MBA), while no significant differences were found between the two groups in terms of efficiency, perspicuity, dependability and stimulation. The overall score for the system usability was not found to differ between the two conditions.

Practical implications

The usability and user experience issues discussed in this study can inform educators and policymakers about the potential of using mobile devices in online assessment practices, as an alternative to desktop computers.

Originality/value

The study is novel, in that it provides quantitative evidence for the usability and user experience of both desktop computers and mobile devices when used in a summative assessment in the context of a higher education course. Study findings can contribute towards the interchangeable usage of desktop computers and mobile devices in assessment practices in higher education.