bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sub-Diffusive Dynamics Lead to Depleted Particle Densities Near Cellular Borders
Authors: Holmes William R. 
Published: October 2018

AbstractIt has long been known that the complex cellular environment leads to anomalous motion of intracellular particles. At a gross level, this is characterized by mean squared displacements that deviate from the standard linear profile. Statistical analysis of particle trajectories has helped further elucidate how different characteristics of the cellular environment can introduce different types of anomalousness. A significant majority of this literature has however focused on characterizing the properties of trajectories that do not interact with cell borders (e.g. cell membrane or nucleus). Numerous biological processes ranging from protein activation to exocytosis however require particles to be near a membrane. This study investigates the consequences of a canonical type of sub-diffusive motion, Fractional Brownian Motion (FBM), and its physical analogue Generalized Langevin Equation (GLE) Dynamics, on the spatial localization of particles near reflecting boundaries. Results show that this type of sub-diffusive motion leads to the formation of significant zones of depleted particle density near boundaries, and that this effect is independent of the specific model details encoding those dynamics. Rather these depletion layers are a natural and robust consequence of the anti-correlated nature of motion increments that is at the core of FBM / GLE dynamics. If such depletion zones are present, it would be of profound importance given the wide array of signaling and transport processes that occur near membranes. If not, that would suggest our understanding of this type of anomalous motion may be flawed. Either way, this result points to the need to further investigate the consequences of anomalous particle motions near cell borders from both theoretical and experimental perspectives.
In-Cell Structural Dynamics of an EGF Receptor during Ligand-induced Dimer-Oligomer Transition
Authors: Kozer N. , Clayton A. H.A. 
Published: October 2018

AbstractThe epidermal growth factor receptor (EGFR) is a membrane protein that regulates cell proliferation, differentiation and survival, and is a drug target for cancer therapy. Ligand-induced activation of the EGFR kinase is generally regarded to require ligand-bound-dimers, while phosphorylation and downstream signalling is modulated by higher-order oligomers. Recent work has unveiled changes in EGFR dynamics from ligand-induced dimerization in membranes extracted from cells, however less is known about the changes in EGFR dynamics that accompany the ligand-induced dimer to tetramer transition in a live cell environment. In the present report, we determine the dynamics of a c-terminal GFP tag attached to EGFR in the unliganded dimer and in the liganded tetramer by means of dynamic depolarization microscopy. We made use of a novel analysis method, the single-frequency polarized phasor ellipse approach, to extract two correlation times on the subnanosecond and super-nanosecond timescales, respectively. EGF binding to the EGFR-GFP dimer lengthened the sub-nanosecond correlation time (from 0.1ns to 1.3ns), and shortened the supernanosecond correlation time (from 210ns to 56ns) of the c-terminal GFP probe. The sub-nanosecond depolarization processes were assigned to electronic energy migration between proximal GFPs in the EGFR dimer or oligomer, while the super-nanosecond correlation times were assigned to nanosecond fluctuations of the GFP probe in the EGFR complex. Accordingly, these results show that ligand binding to the extracellular domain increased the average separation between the c-terminal tags and increased their rotational mobility. We propose that the dynamics are linked to an inhibitory function of the c-terminal tail in the un-liganded dimer and to the requirement of facile stochastic switching between kinase activation and cytoplasmic adaptor/effector binding in the active tetramer.
Patterns of hybrid seed inviability in perennials of theMimulus guttatussp. complex reveal a potential role of parental conflict in reproductive isolation
Authors: Coughlan Jenn M. , Brown Maya Wilson , Willis John H. 
Published: October 2018

SummaryGenomic conflicts may play a central role in the evolution of reproductive barriers. Theory predicts that early-onset hybrid inviability may stem from conflict between parents for resource allocation to offspring. Here we describeM. decorus;a group of cryptic species within theM. guttatusspecies complex that are largely reproductively isolated by hybrid seed inviability (HSI). HSI betweenM. guttatusandM. decorusis common and strong, but populations ofM. decorusvary in the magnitude and directionality of HSI withM. guttatus. Patterns of HSI betweenM. guttatusandM. decorus, as well as withinM. decorusconform to the predictions of parental conflict: (1) reciprocal F1s exhibit size differences and parent-of-origin specific endosperm defects, (2) the extent of asymmetry between reciprocal F1 seed size is correlated with asymmetry in HSI, and (3) inferred differences in the extent of conflict predict the extent of HSI between populations. We also find that HSI is rapidly evolving, as populations that exhibit the most HSI are each others’ closest relative. Lastly, while all populations are largely outcrossing, we find that the differences in the inferred strength of conflict scale positively with π, suggesting that demographic or life history factors other than mating system may also influence the rate of parental conflict driven evolution. Overall, these patterns suggest the rapid evolution of parent-of-origin specific resource allocation alleles coincident with HSI within and betweenM. guttatusandM. decorus.Parental conflict may therefore be an important evolutionary driver of reproductive isolation.
Chronic intermittent ethanol and acute stress similarly modulate BNST CRF neuron activity via noradrenergic signaling
Authors: Snyder Angela E , Winder Danny G , Silberman Yuval 
Published: October 2018

AbstractRelapse is a critical barrier to effective long-term treatment of alcoholism, and stress is often cited as a key trigger to relapse. Numerous studies suggest that stress-induced reinstatement to drug seeking behaviors is mediated by norepinephrine (NE) and corticotropin releasing factor (CRF) signaling interactions in the bed nucleus of the stria terminalis (BNST), a brain region critical to many behavioral and physiologic responses to stressors. Here we sought to directly examine the effects of NE on BNST CRF neuron activity and determine if these effects may be modulated by chronic intermittent EtOH (CIE) exposure or a single restraint stress. Utilizing whole-cell patch clamp electrophysiological techniques in CRF-tomato reporter mice, we found that NE depolarized BNST CRF neurons in naïve mice in a β-adrenergic receptor (AR) dependent mechanism. CRF neurons from CIE or stress-exposed mice had significantly elevated basal resting membrane potential compared to naïve mice. Furthermore, CIE and stress individually disrupted the ability of NE to depolarize CRF neurons, suggesting that both stress and CIE utilize β-AR signaling to modulate BNST CRF neurons. Neither stress nor CIE altered the ability of exogenous NE to inhibit evoked glutamatergic transmission onto BNST CRF neurons, a mechanism previously shown to be α-AR dependent. Altogether these findings suggest that stress and CIE interact with β-AR signaling to modulate BNST CRF neuron activity, potentially disrupting the α/β-AR balance of BNST CRF neuronal excitability. Restoration of α/β-AR balance may lead to novel therapies for the alleviation of many stress-related disorders.
Identification of Pirin as a Molecular Target of the CCG-1423/CCG- 203971 Series of Anti-Fibrotic and Anti-Metastatic Compounds
Authors: Lisabeth Erika M. , Kahl Dylan , Gopallawa Indiwari , Haynes Sarah E. , Misek Sean A. , Campbell Phillip L. , Dexheimer Thomas S. , Khanna Dinesh , Fox David A. , Jin Xiangshu , Martin Brent R. , Larsen Scott D. , Neubig Richard R. 
Published: October 2018

AbstractA series of compounds (including CCG-1423 and CCG-203971) discovered through an MRTF/SRF dependent luciferase screen has shown remarkable efficacy in a variety of in vitro and in vivo models, including melanoma metastasis and bleomycin-induced fibrosis. Although these compounds are efficacious, the molecular target is unknown. Here, we describe affinity isolation-based target identification efforts which yielded pirin, an iron-dependent co-transcription factor, as a target of this series of compounds. Using biophysical techniques including isothermal titration calorimetry and X-ray crystallography, we verify that pirin binds these compounds in vitro. We also show with genetic approaches that pirin modulates MRTF-dependent SRE.L Luciferase activation. Finally, using both siRNA and a previously validated pirin inhibitor, we show a role for pirin in TGF-p induced gene expression in primary dermal fibroblasts. A recently developed analog, CCG-257081, which co-crystallizes with pirin, is also effective in the prevention of bleomycin-induced dermal fibrosis.
Testing the fast consolidation hypothesis of retrieval-mediated learning
Authors: Ferreira C.S. , Charest I. , Wimber M. 
Published: October 2018

AbstractThe testing-effect, or retrieval-mediated learning, is one of the most robust effects in memory research. It shows that actively and repeatedly retrieving information, compared to merely restudying it, improves long-term retention. Surprisingly, little is known about the neurocognitive mechanisms underlying this phenomenon. Attempting to fill this gap, a recent framework proposed that retrieval acts as a fast memory consolidation mechanism, stabilizing memories through online reactivation, similar to memory replay during offline (e.g. sleep) consolidation. In this fMRI study, we empirically tested the predictions derived from this framework.We predicted that reactivation during retrieval allows memories to become embedded in neocortex, creating an additional route to access the memory trace and rendering it less hippocampus-dependent. Participants encoded scene-object pairs and either retrieved or restudied the objects over two sessions, two days apart. We analysed univariate and multivariate changes in brain activity specific to retrieval but not restudy, and tested whether the predicted changes occur rapidly within a session, or evolve slowly, across the two days.Results showed that medial prefrontal cortex activation increased across retrieval trials within one session, consistent with a fast consolidation account. Hippocampal activity decreased across sessions, suggesting a slower mechanism. Moreover, Representational Similarity Analyses (RSA) showed that consecutive retrieval attempts strengthen both higher-level semantic and episode-specific information in parietal areas, both across but not within sessions. Our findings suggest that retrieval supports the online creation of a neocortical trace, which becomes increasingly relevant at long delays when hippocampus-dependent episodic details would otherwise have faded.Significance statementRepeated remembering strengthens memories much more so than repeated learning. The aim of this study was to shed light onto the poorly understood neurocognitive underpinnings of retrieval-mediated learning. We tested a novel framework proposing that a memory’s stabilization via retrieval relies on mechanisms akin to those involved in offline systems consolidation. Observing the retrieval-induced neural pattern changes across different timescales, we find that retrieval stabilizes semantic and episodic aspects of the original memories, and produces increases in prefrontal activity and decreases in hippocampal activity that are consistent with the consolidation view, but not necessarily with a fast acting mechanism. Our findings inform cognitive theories of the testing effect, suggesting that retrieval produces its benefits by interacting with hippocampal-neocortical consolidation mechanisms.
Assessing the sustainability of biofuel production from camelina in Spain, results of the ITAKA project – analysis of GHG emissions
Authors: Guittet Mélanie , Capezzali Massimiliano , Hernando Gonzalo , Herreras Yuri 
Published: October 2018

Purpose
With the rapid growth and increased consumption of biofuels worldwide, and the multitude of policy decisions supporting this expansion, growing concerns about the biofuels sustainability have arisen. Therefore, the European project “ITAKA”, aiming at supporting the development of aviation biofuels in an economically, socially and environmentally sustainable manner, has devoted considerable effort to take sustainability into account, in a quantitative and qualitative manner. This paper aims to calculate a robust assessment of a life-cycle greenhouse gas (GHG) for the entire ITAKA value chain.

Design/methodology/approach
The calculation for the produced bio jet fuel has been set up using the roundtable on sustainable biomaterials (RSB) European Union (EU) renewable energy directive (RED) methodology, through the online RSB tool. This pathway includes feedstock production, feedstock processing, biofuel production, biofuel distillation and all transport steps involved.

Findings
A significant reduction in GHG emissions has been demonstrated, up to 66 per cent emission reduction if one considers a mature pathway for the entire ITAKA biofuel chain.

Practical implications
The camelina oil produced can be sustainable according to RSB and RSB EU RED schemes if the practices defined in the project are applied.

Originality/value
Application of different frameworks (actual vs theoretical) to the ITAKA value chain has aimed at testing and demonstrating the commercial application of the sustainability standards in Europe and the readiness of biofuels in Europe as a major means to decrease GHG emissions in aviation.
The effect of wing-tip propulsors on Icaré 2 aeroelasticity
Authors: Chajec Wojciech , Krzymien Wieslaw A. , Strohmayer Andreas 
Published: October 2018

Purpose
The separation of energy conversion and propulsor is a promising aspect of hybrid-electric propulsion systems, allowing for increased installation efficiencies and setting the basis for distributed propulsion concepts. University of Stuttgart’s Institute of Aircraft Design has a long experience with electrically powered aircraft, starting with Icaré 2, a solar-powered glider flying, since 1996. Icaré 2 recently has been converted to a three-engine motor glider with two battery-powered wing-tip propellers, in addition to the solar-powered main electric motor. This adds propulsion redundancy and will allow analyzing yaw control concepts with differential thrust and the propeller-vortex interaction at the wing-tip. To ensure airworthiness for this design modification, new ground vibration tests (GVTs) and flutter calculations are required. The purpose of this paper is to lay out the atypical approach to test execution due to peculiarities of the Icaré 2 design such as an asymmetrical aileron control system, the long wing span with low frequencies of the first mode and elevated wing tips bending under gravity and thus affecting the accuracy of the wing torsion frequency measurements.

Design/methodology/approach
A flutter analysis based on GVT results is performed for the aircraft in basic configuration and with wing tip propulsors in pusher or tractor configuration. Apart from the measured resonant modes, the aircraft rigid body modes and the control surface mechanism modes are taken into consideration. The flutter calculations are made by a high-speed, low-cost software named JG2 based on the strip theory in aerodynamics and the V-g method of flutter problem solution.

Findings
With the chosen atypical approach to GVT the impact of the suspension on the test results was shown to be minimal. Flutter analysis has proven that the critical flutter speed of Icaré 2 is sufficiently high in all configurations.

Practical implications
The atypical approach to GVT and subsequent flutter analysis have shown that the effects of wing-tip propulsors on aeroelasticity of the high aspect ratio configuration do not negatively affect flutter characteristics. This analysis can serve as a basis for an application for a permit to fly.

Originality/value
The presented methodology is valuable for the flutter assessment of aircraft configurations with atypical aeroelastic characteristics.
Cross-cultural effects of self-discrepancy on the consumption of counterfeit branded luxuries
Authors: Xiao Jiongen , Li Chunyu , Peng Ling 
Published: October 2018

PurposeConsumers’ motivations for purchasing counterfeit branded luxuries are a topic of heated discussion amongst academics and practitioners. Drawing on self-discrepancy theory, the purpose of this paper is to examine the effects of actual-ideal self-discrepancy on consumers’ attitudes towards counterfeit branded luxuries. It investigates how self-monitoring and perceived social risk moderate this effect. Furthermore, it explores cross-cultural differences in the impact of actual-ideal self-discrepancy.Design/methodology/approachA pilot study provides preliminary evidence that highlights the importance of actual-ideal self-discrepancy in counterfeit consumption. Based upon a large-scale survey across Hong Kong, the USA and Australia, the principal study explores the moderating effect of self-monitoring and perceived social risk as well as cross-cultural differences.FindingsThe results indicate that self-discrepancy increases consumers’ tendency to engage in symbolic consumption, and that consumption of counterfeit branded luxuries can serve the social function of self-expression to reduce the discomfort induced by self-discrepancy. Self-monitoring and perceived social risk have significant moderating effects, with the former strengthening and the latter attenuating this effect. Moreover, the effect of self-discrepancy is more pronounced amongst individualistic consumers than collectivistic consumers.Originality/valueThis is the first study to highlight the significance of self-discrepancy in the consumption of counterfeit branded luxuries. It examines the important moderating effects of self-monitoring and perceived social risk. Consumers from collectivistic and individualistic cultures define their self-concept differently, thus the findings provide meaningful cross-cultural information on the impact of self-discrepancy in counterfeit consumption.
Disclosure of corporate sustainability performance and firm performance in Asia
Authors: Laskar Najul , Gopal Maji Santi 
Published: October 2018

PurposeThe purpose of this paper is to examine the disclosure pattern of corporate sustainability (CS) and the influence of sustainability reporting on firm performance of four countries in Asia – Japan, South Korea, Indonesia and India.Design/methodology/approachThe authors have collected the sustainability reports and annual reports of 111 firms from four Asian countries for a period of six years. Based on the framework of Global Reporting Initiatives (GRI, 3 and 3.1), content analysis is used for calculating the disclosure score of corporate sustainability performance (CSP). These scores are further used to examine the impact on firm performance by employing a panel data regression model.FindingsThe study finds that the average level and quality of disclosure are the highest for Japanese firms, followed by India and South Korea. However, in the case of Indonesia, the average score is very low. Further, the study finds a significant difference in the disclosure of overall sustainability as well as components of sustainability between the countries. The regression results indicate the positive impact of CSP (both in terms of level and quality) on MBR. Specifically, the outcome of the regression model reveals that both the level and quality disclosure of CS are crucial for enhancing firm value for both the developed and developing countries of Asia. Moreover, the relative influence of CSP (both in terms of level and quality) on firm performance is found to be more in developed countries than the developing countries of Asia.Originality/valueThis is the first comprehensive study in the Asian context to investigate the disclosure pattern of CSP and also examine the association between CSP and firm performance by employing the panel data model. The outcome of this study is useful for policy implication.
Does board gender diversity affect the transparency of corporate political disclosure?
Authors: DeBoskey D.G. , Luo Yan , Wang Jeff 
Published: October 2018

Purpose
The purpose of this paper is to examine the influence of board gender diversity on the transparency of corporate political disclosure (CPD).

Design/methodology/approach
Two empirical proxies, CPD transparency and policy transparency, are constructed from a data set jointly produced by the Center of Political Activity and the Carol and Lawrence Zicklin Center for Business Ethics Research. The CPD transparency score measures the level of transparency in voluntary corporate disclosure of the amount of political contributions and the identity of the recipients as well as the titles and names of the executives who authorize the political spending. The policy transparency score measures the level of transparency in the voluntary disclosure of the policies governing corporate political spending. Board gender diversity is measured by the percentage of women on the board of directors.

Findings
Higher proportions of female directors are associated with more transparent disclosure of political contributions after controlling for a set of corporate governance and firm-level variables.

Originality/value
This study is the first to examine whether and how gender-diversified boards enhance the transparency of CPD. It contributes to the literature by providing evidence that gender-diversified boards enhance corporate governance.