bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intraoperative contrast-enhanced ultrasound for cerebral glioma resection and the relationship with microvessel density
Authors: Wang Jia , Liu Xi , Yang Yilin , Duan Yunyou 
Published: January 2019

ABSTRACTPurposeWe studied the value of intraoperative contrast-enhanced ultrasound (iCEUS) for real-time monitoring of resection of cerebral gliomas, and analyzed the relationship between CEUS parameters and microvessel density (MVD) of different pathologic grades of cerebral gliomas.Materials and MethodsICEUS was performed in 49 patients with cerebral gliomas. The enhancement characteristics of cerebral gliomas were observed before and after tumor resection. The number of microvessels was counted by immunostaining with anti-CD34. Differences in these quantitative parameters in cerebral gliomas were compared and subjected to a correlation analysis with MVD.ResultsThe color Doppler flow classification within lesions were significantly different before and after iCEUS (p<0.05). The assessment of iCEUS parameters and tumor MVD showed that cerebral gliomas of different pathological grades had different characteristics. The time-to-peak (Tmax) was significantly shorter, the peak intensity (PI) and MVD were significantly higher in high-grade cerebral gliomas than in low-grade cerebral gliomas (p<0.05). According to the immunostaining, PI was positively (r=0.637) correlated with MVD and Tmax was negatively (r=–0.845) correlated with MVD.ConclusionICEUS may determine the borders of lesions more clearly, indicate the microvascular perfusion in real time, and be helpful in understanding the cerebral gliomas grade.
Piezo1 is required for outflow tract and aortic valve development
Authors: Faucherre Adèle , Moha ou Maati Hamid , Nasr Nathalie , Pinard Amélie , Theron Alexis , Odelin Gaëlle , Desvignes Jean-Pierre , Salgado David , Collod-Béroud Gwenaëlle , Avierinos Jean-François , Lebon Guillaume , Zaffran Stéphane , Jopling Chris 
Published: January 2019

AbstractAims-During embryogenesis, the onset of circulatory blood flow generates a variety of hemodynamic forces which reciprocally induce changes in cardiovascular development and performance. It has been known for some time that these forces can be detected by as yet unknown mechanosensory systems which in turn promote cardiogenic events such as outflow tract and aortic valve development. PIEZO1 is a mechanosensitive ion channel present in endothelial cells where it serves to detect hemodynamic forces making it an ideal candidate to play a role during cardiac development. We sought to determine whether PIEZO1 is required for outflow tract and aortic valve development.Methods and results-By analysing heart development in zebrafish we have determined thatpiezo1is expressed in the developing outflow tract where it serves to detect hemodynamic forces. In particular, we have found that mechanical forces generated during the cardiac cycle activate Piezo1 which triggers nitric oxide to be released in the outflow tract. Consequently, disrupting Piezo1 signalling leads to defective outflow tract and aortic valve development and indicates this gene may be involved in the etiology of congenital heart diseases. Based on these findings, we analysed genomic data generated from a cohort of bicuspid aortic valve patients and identified 3 probands who each harboured a novel variant inPIEZO1. Subsequentin vitroandin vivoassays indicates that these variants behave as dominant negatives leading to an inhibition of normal PIEZO1 mechanosensory activity and defective aortic valve development.Conclusion-These data indicate that the mechanosensitive ion channelpiezo1is required for OFT and aortic valve development and, furthermore, dominant negative variants ofPIEZO1appear to be associated with BAV in humans.
C/EBPδ demonstrates a dichotomous role in tumor initiation and promotion of epithelial carcinoma
Authors: Sowamber Ramlogan , Chehade Rania , Bitar Mahmoud , Dodds Leah , Milea Anca , Slomovitz Brian , Shaw Patricia A , George Sophia HL 
Published: January 2019

AbstractC/EBPδ(CEBPD), a gene part of the highly conserved basic-leucine zipper (b-ZIP) domain of transcriptional factors, is downregulated in 65% of high grade serous carcinoma of the ovary (HGSC). Overexpression ofC/EBPδin different tumors as glioblastoma and breast cancer either promotes tumor progression or inhibits growth. Despite these contradictory roles in different cancer types, we show thatC/EBPδoverexpression has a consistent function of downregulating proliferation and promoting migration in fallopian tube epithelial cells (FTE). We show that the FTE have both mesenchymal and epithelial cell characteristics. Further, our data supports a role forC/EBPδas an early regulatory transcriptional factor that promotes a mesenchymal to epithelial (MET) phenotype by upregulating E-cadherin and downregulating vimentin and N-cadherin in FTE cells. We demonstrate that overexpression ofC/EBPδin ovarian and breast cancer cell lines have consistent effects and phenotype as the FTE cells. Our findings suggest a role forC/EBPδin the early events of ovarian serous carcinogenesis which may be used to help further understand how the disease develops from a premalignant cells.
Behavior influences range limits and patterns of coexistence across an elevational gradient in tropical bird diversity
Authors: Freeman Benjamin G , Tobias Joseph A , Schluter Dolph 
Published: January 2019

AbstractDoes competition influence patterns of coexistence between closely related taxa? Here we address this basic question in ecology by analyzing patterns of range overlap between related bird species (“sister pairs”) distributed along a Neotropical elevational gradient. We explicitly contrast the behavioral dimension of interspecific competition (interference competition) with similarity in resource acquisition traits (exploitative competition). We find that behavioral interactions are generally important in setting elevational range limits and preventing coexistence of closely related species. Specifically, close relatives that defend year-round territories tend to live in non-overlapping elevational distributions, while close relatives that do not defend territories tend to broadly overlap in distribution. In contrast, neither similarity in beak morphology nor evolutionary relatedness was associated with patterns of range limitation. Our main result is that interference competition can be an important driver of species ranges at the scale of entire diverse assemblages. Consequently, we suggest that behavioral dimensions of the niche should be more broadly incorporated in macroecological studies.
Mutational Landscape of Spontaneous Base Substitutions and Small Indels in Experimental Caenorhabditis elegans Populations of Differing Size
Authors: Konrad Anke , Brady Meghan J. , Bergthorsson Ulfar , Katju Vaishali 
Published: January 2019

ABSTRACTExperimental investigations into the rates and fitness effects of spontaneous mutations are fundamental for our understanding of the evolutionary process. To gain insights into the molecular and fitness consequences of spontaneous mutations, we conducted a mutation accumulation (MA) experiment at varying population sizes in the nematode Caenorhabditis elegans, evolving 35 lines in parallel for 409 generations at three population sizes (N = 1, 10, 100 individuals). Here, we focus on nuclear SNPs and small indels under minimal influence of selection, as well as their accrual rates in larger populations under greater selection efficacy. The spontaneous rates of base substitutions and small indels are 1.84 × 10−9 substitutions and 6.84 × 10−10 changes /site/generation, respectively. Small indels exhibit a deletion-bias with deletions exceeding insertions by three-fold. Notably, there was no correlation between the frequency of base substitutions, nonsynonymous substitutions or small indels with population size. These results contrast with our previous analysis of mtDNA mutations and nuclear copy-number changes in these MA lines, and suggest that nuclear base substitutions and small indels are under less stringent purifying selection compared to the former mutational classes. A transition bias was observed in exons as was a near universal base substitution bias towards A/T. Strongly context-dependent base substitutions, where 5’–T and 3’–As increase the frequency of A/T → T/A transversions, especially at the boundaries of A or T homopolymeric runs, manifest as higher mutation rates in (i) introns and intergenic regions relative to exons, (ii) chromosomal cores versus arms and tips, and (iii) germline-expressed genes.
Comparative analysis of sfRNA in the genome of pre-epidemic and epidemic Zika viruses for host interacting proteins potentially related to the recent epidemic
Authors: Desingu P.A. 
Published: January 2019

AbstractZika virus (ZIKV), circulating in more than 70 countries since 2014, is causing severe developmental abnormality to compare to pre-epidemic infection. ZIKV related flaviviruses as the ability to produce subgenomic flaviviral RNAs (sfRNAs) which are associated with pathogenicity in foetal mice. This study, delineate the increased virulence of ZIKV through sfRNA mediated host protein interaction. Phylogenetically ZIKV sfRNA formed three distinct clades of African, Asian and American strains. Compare with preepidemic, the epidemic ZIKV sfRNA has genetic, RNA secondary structure and host protein interacting profile diversity. Interestingly this study found that ZIKV sfRNA interacting proteins involved in the neuronal development, differentiation, proliferation, and apoptosis along with spermatogenesis, host immunity and viral pathogenesis. The difference in the interaction profile and interaction strength between pre-epidemic and epidemic virus could be the reason for the increased virulence of the recent epidemic viruses. Targeting this protein will be the potent choice for antiviral drug designing.
On measuring selection in cancer from subclonal mutation frequencies
Authors: Bozic Ivana , Paterson Chay , Waclaw Bartlomiej 
Published: January 2019

ABSTRACTRecently available cancer sequencing data have revealed a complex view of the cancer genome containing a multitude of mutations, including drivers responsible for cancer progression and neutral passengers. Measuring selection in cancer and distinguishing drivers from passengers have important implications for development of novel treatment strategies. It has recently been argued that a third of cancers are evolving neutrally, as their mutational frequency spectrum follows a 1/f power law expected from neutral evolution in a particular intermediate frequency range. We study a stochastic model of cancer evolution and derive a formula for the probability distribution of the cancer cell frequency of a subclonal driver, demonstrating that driver frequency is biased towards 0 and 1. We show that it is difficult to capture a driver mutation at an intermediate frequency, and thus the calling of neutrality due to a lack of such driver will significantly overestimate the number of neutrally evolving tumors. Our approach provides precise quantification of the validity of the 1/f statistic across the entire range of all relevant parameter values. Our results are also applicable to the question of distinguishing driver and passenger mutations in a general exponentially expanding population.
Anchor shape gap coupled patch antenna for WiMAX and WLAN applications
Authors: Singh Vivek , Mishra Brijesh , Singh Rajeev 
Published: January 2019

Purpose
Purpose of this study is to design a compact gap coupled anchor shape patch antenna for wireless local area network/high performance radio local area network and worldwide interoperability for microwave access applications.

Design/methodology/approach
An anchor shape microstrip antenna is conceived, designed, simulated and measured. The anchor shape antenna is transformed to its rectangular equivalent by conserving the patch area. Modeling and simulation of the antenna is performed by Ansys high frequency structure simulator (HFSS) electromagnetic solver based on the concept of finite element method. The simulated results are experimentally verified by using Agilent E5071C vector network analyzer. Theoretical analysis of an electromagnetically gap coupled anchor shape microstrip patch antenna has been performed by obtaining the lumped element equivalent of the transformed antenna.

Findings
The proposed antenna has a compact conducting patch of dimension 0.26λ × 0.12λ mm2 (λ is calculated at lower resonating frequency of 3.56 GHz) with impedance bandwidths of 100 and 140 MHz and antenna gains of 1.91 and 3.04 dB at lower resonating frequency of 3.56 GHz and upper resonating frequency of 5.4 GHz, with omni-directional radiation pattern.

Originality/value
In literature, one does not encounter anchor shape antenna using the concept of gap coupling and parasitic patches. The design has been optimized for wireless local area network/worldwide interoperability for microwave access applications with a relatively low patch area (291.12 mm2) as compared to other reported antennas for wireless local area network/worldwide interoperability for microwave access applications. Transformed antenna and the actual experimental antenna behavior varies, but the resonant frequencies of the transformed antenna as observed by theoretical analysis and simulated results (by high frequency structure simulator) are reasonably close, and the percentage difference between the resonant frequencies (both at lower and upper bands) is within the permissible limit of 1-2.5 per cent. Results confirm the theoretical proposition of transformation of shapes in antenna design, which allows a designer to adapt the design shape according to the application.
Modelling of sand production using a mesoscopic bonded particle lattice Boltzmann method
Authors: Wang Min , Feng Y.T. , Zhao Ting T. , Wang Yong 
Published: January 2019

Purpose
Sand production is a challenging issue during hydrocarbon production in the oil and gas industry. This paper aims to investigate one sand production process, i.e. transient sand production, using a novel bonded particle lattice Boltzmann method. This mesoscopic technique provides a unique insight into complicated sand erosion process during oil exploitation.

Design/methodology/approach
The mesoscopic fluid-particle coupling is directly approached by the immersed moving boundary method in the framework of lattice Boltzmann method. Bonded particle method is used for resolving the deformation of solid. The onset of grain erosion of rocks, which are modelled by a bonded particle model, is realised by breaking the bonds simulating cementation when the tension or tangential force exceeds critical values.

Findings
It is proved that the complex fluid–solid interaction occurring at the pore/grain level can be well captured by the immersed moving boundary scheme in the framework of the lattice Boltzmann method. It is found that when the drawdown happens at the wellbore cavity, the tensile failure area appears at the edge of the cavity. Then, the tensile failure area gradually propagates inward, and the solid particles at the tensile failure area become fluidised because of large drag forces. Subsequently, some eroded particles are washed out. This numerical investigation is demonstrated through comparison with the experimental results. In addition, through breaking the cementation, which is simulated by bond models, between bonded particles, the transient particle erosion process is successfully captured.

Originality/value
A novel bonded particle lattice Boltzmann method is used to investigate the sand production problem at the grain level. It is proved that the complex fluid–solid interaction occurring at the pore/grain level can be well captured by the immersed moving boundary scheme in the framework of the lattice Boltzmann method. Through breaking the cementation, which is simulated by bond models, between bonded particles, the transient particle erosion process is successfully captured.
High performance work practices, organizational performance and strategic thinking
Authors: Alatailat Maher , Elrehail Hamzah , Emeagwali Okechukwu Lawrence 
Published: January 2019

PurposeDrawing on a number of strategic management theories, the purpose of this paper is to explore the relationship between strategic thinking (in other words, systems perspective, focused intent, intelligent opportunism, thinking in time and hypothesis-driven analysis) and organizational performance. It also investigates whether the notion and content of high performance work practices, as identified in developed countries, can be used to amplify the effects of strategic thinking within the banking industry in a developing country.Design/methodology/approachUtilizing cross-sectional data obtained from commercial banks in Jordan, this paper applied structural equation modeling (SEM) to examine the banking sector in a developing country. Data were collected through self-administered questionnaires.FindingsAccording to the results, focused intent, intelligent opportunism, thinking in time and hypothesis-driven analysis have positive impacts on organizational performance, except when considered from the systems perspective. Consequently, high performance work practices were found to only moderate the relationship between focused intent, intelligent opportunism, thinking in time and organizational performance.Originality/valueThe authors examined the impact of strategic thinking on the organizational performance through the moderation role of high performance work practices. The results of this paper extend the existing literature by providing evidence from Jordan, a developing country outside of the western world.
Wagner’s law and governments’ functions: granularity matters
Authors: Jalles Joao 
Published: January 2019

PurposeThe purpose of this paper is to assess the responses of different categories of government spending to changes in economic activity. In other words, the authors empirically revisit the validation of the Wagner’s law in a sample of 61 advanced and emerging market economies between 1995 and 2015.Design/methodology/approachThe authors do so via panel data instrumental variables and time-series SUR approaches.FindingsEvidence from panel data analyses show that the Wagner’s law seems more prevalent in advanced economies and when countries are growing above potential. However, such result depends on the government spending category under scrutiny and the functional form used. Country-specific analysis revealed relatively more cases satisfying Wagner’s proposition within the emerging markets sample. The authors also found evidence of counter-cyclicality in several spending items. All in all, the Wagner’s regularity seems more the exception than the norm.Originality/valueWhile in the literature on the size of the public sector with respect to a country’s level of economic development has received much attention, the authors make several novel contributions: since some economists criticized Wagner’s law because of ambiguity of the measurement of government expenditure (Musgrave, 1969), instead of looking at aggregate public expenditures, the authors go much more granular into the different functions of government (to this end, the authors use the Classification of Functions of the Government nomenclature). The authors check the validity of the Law via an instrumental variable approach in a panel setting; after that, the authors take into account the phase of the business cycle using a new filtering technique to compute potential GDP (output gap); then, the authors cross-check the baseline results by considering alternative functional form specifications of the Law; and finally, the authors look at individual countries one at the time via SUR analysis.
Asymmetric information phenomenon in the link between CEO pay and firm performance
Authors: Olaniyi Clement 
Published: January 2019

PurposeThe purpose of this paper is to examine the asymmetric behavior between CEO pay and firm performance in Nigeria.Design/methodology/approachThe study adopts a two-step dynamic panel generalized method of moments (GMM) to reveal asymmetric responses of CEO pay to positive and negative shocks in firm performance.FindingsThe research outcomes of a two-step dynamic panel GMM) adopted reveal asymmetric responses of CEO pay to positive and negative shocks in firm performance. This implies that CEOs are handsomely compensated for good performance, but not punished for poor performance.Originality/valueThe study, therefore, suggests that CEO pay fails to serve as an internal corporate governance mechanism to alleviate agency problem in Nigeria’s listed firms.
Testing the Distraction Hypothesis: Do extrafloral nectaries reduce ant‐pollinator conflict?
Authors: Villamil Nora , Boege Karina , Stone Graham N. 
Published: January 2019

AbstractAnt guards protect plants from herbivores, but can also hinder pollination by damaging reproductive structures and/or repelling pollinators. Natural selection should favour the evolution of plant traits that deter ants from visiting flowers during anthesis, without waiving their defensive services. The Distraction Hypothesis posits that rewarding ants with extrafloral nectar could reduce their visitation of flowers, reducing ant‐pollinator conflict while retaining protection of other structures.We characterised the proportion of flowers occupied by ants and the number of ants per flower in a Mexican ant‐plant,Turnera velutina. We clogged extrafloral nectaries on field plants and observed the effects on patrolling ants, pollinators and ants inside flowers, and quantified the effects on plant fitness. Based on the Distraction Hypothesis, we predicted that preventing extrafloral nectar secretion should result in fewer ants active at extrafloral nectaries, more ants inside flowers and a higher proportion of flowers occupied by ants, leading to ant‐pollinator conflict, with reduced pollinator visitation and reduced plant fitness.Overall ant activity inside flowers was low. Preventing extrafloral nectar secretion through clogging reduced the number of ants patrolling extrafloral nectaries, significantly increased the proportion of flowers occupied by ants from 6.1% to 9.7%, and reduced plant reproductive output through a 12% increase in the probability of fruit abortion. No change in the numbers of ants or pollinators inside flowers was observed. This is the first support for the Distraction Hypothesis obtained under field conditions, showing ecological and plant fitness benefits of the distracting function of extrafloral nectar during anthesis.Synthesis.Our study provides the first field experimental support for the Distraction Hypothesis, suggesting that extrafloral nectaries located close to flowers may bribe ants away from reproductive structures during the crucial pollination period, reducing the probability of ant occupation of flowers, reducing ant‐pollinator conflict and increasing plant reproductive success.