bluuebunny/crossref_metadata_2025_split huggingface dataset:
Precipitation of Hydrogen Energetic Neutral Atoms at the Upper Atmosphere of Mars
Authors: Wang X.‐D. , Alho M. , Jarvinen R. , Kallio E. , Barabash S. , Futaana Y. 
Published: July 2018

AbstractWe study the properties of neutral hydrogen atoms precipitating onto the upper atmosphere of Mars. Energetic neutral atoms (ENAs) are produced by the charge exchange process between protons of solar wind (both upstream and shocked) as well as planetary origins and the Martian exospheric neutrals. Using a global hybrid plasma model for Mars‐solar wind interaction combined with an up‐to‐date exosphere model of Mars, we calculate the fluxes, spatial distributions, energy spectra, and direction distributions of hydrogen ENAs (H‐ENAs) at the Martian exobase for each source proton population. H‐ENAs originating from the upstream solar wind region and the magnetosheath dominate the precipitation. Two percent of the solar wind flux penetrates through the magnetic barrier as H‐ENAs under solar minimum conditions. The precipitating solar wind H‐ENA flux is axially symmetric about Sun‐Mars line, while the magnetosheath and planetary H‐ENAs have higher fluxes and a more‐extended precipitation area in the hemisphere where the convection electric field is pointing away from the planet, causing a significant precipitation beyond the terminator. The observed asymmetry is consistently explained by an asymmetric plasma flow in the dayside magnetosheath. The solar wind dynamic pressure increases the solar wind H‐ENA precipitation normalized by the upstream proton flux, due to a closer bow shock position and thus a higher exospheric column density for charge exchange. The spatial distribution of the magnetosheath solar wind and planetary H‐ENAs becomes more axially symmetric with increased dynamic pressure. The solar wind interaction with Mars exhibits more gas‐dynamic‐like signatures for higher dynamic pressure.
Investigating High‐Latitude Energy Deposition Events Occurring During the 17 January 2005 Geomagnetic Storm
Authors: Horvath Ildiko , Lovell Brian C. 
Published: July 2018

AbstractThis study investigates the coupled ionosphere‐thermosphere system during the 17 January 2005 geomagnetic storm. Multiinstrument satellite data are utilized to track polar convection and flow channels (FCs) in the topside ionosphere to compute Poynting flux values approximating electromagnetic energy and to detect localized neutral density increases and also to signal FC signatures in the thermosphere. Our main aim is to identify energy input regions during various events when localized neutral density increases developed. Such events are illustrated in five scenarios covering both hemispheres. These scenarios demonstrate the development of a cusp enhancement above/within FC‐1 associated with newly open field lines and polar cap enhancements above/within FC‐2, FC‐3, and FC‐4 commonly associated with old open field lines. Localized Poynting flux intensifications within these FCs demonstrate energy deposition continuing along old open field lines in the polar cap. The close correlation of these Poynting flux intensifications with their respective cusp and polar cap enhancements, via their underlying FCs through which the electromagnetic energy was deposited, provide observational evidence that these enhancements were generated by their associated energy inputs. These observational results lead to the conclusions that a main region of high‐latitude energy deposition was (i) the polar cap (>78° magnetic latitude) producing polar cap enhancements (scenarios 1–3), (ii) the prenoon auroral zone producing a cusp enhancement (scenario 4), and (iii) both the polar cap producing a polar cap enhancement and the auroral zone (scenario 5).
Three‐Dimensional Electrical Resistivity Modeling to Elucidate the Crustal Magma Supply System Beneath Aso Caldera, Japan
Authors: Hata M. , Matsushima N. , Takakura S. , Utsugi M. , Hashimoto T. , Uyeshima M. 
Published: July 2018

AbstractA magma supply system is identified in the upper crust beneath Aso caldera, Japan, appearing as a conductive anomaly via three‐dimensional electrical resistivity modeling. Aso caldera contains numerous postcaldera volcanoes, with Naka‐dake cone recently experiencing eruptions at the first crater, including an explosive eruption that ejected volcanic ash 11,000 m into the air in October 2016. The magma supply system imaged by the resistivity model consists of four key components: a magma reservoir at ~17 km depth that corresponds to the Conrad discontinuity, a magma‐filled crack‐propagation zone that extends obliquely from the magma reservoir, another magma reservoir centered at 6 km depth, and an upright crack‐intrusion zone at 2–4 km depth. The shape of the conductive anomaly is consistent with the regional stress regime, with the locations of the low‐velocity anomalies and a deformation source found beneath the caldera. This anomaly is therefore defined as the magma supply system, which feeds magma to the first crater of the Naka‐dake eruptions. The averaged melt fractions of the upper magma reservoir are estimated to be 3%–4% for 89.3 km3 of the reservoir and 96%–99% for 6.3 km3, with resistivity thresholds of <40 and <1 Ωm, respectively. Furthermore, the resistivity model detects three conductive anomalies in Aso caldera that are associated with an aqueous fluid‐flow system in the region. The resistivity model also suggests that the resistivity distribution can play an important role in characterizing the stress regime based on the distribution of earthquake clusters in the upper crust beneath the caldera.
Structure of the mouse TRPC4 ion channel
Authors: Duan Jingjing , Li Jian , Zeng Bo , Chen Gui-Lan , Peng Xiaogang , Zhang Yixing , Wang Jianbin , Clapham David E. , Li Zongli , Zhang Jin 
Published: July 2018

AbstractMembers of the transient receptor potential (TRP) ion channels conduct cations into cells. They mediate functions ranging from neuronally mediated hot and cold sensation to intracellular organellar and primary ciliary signaling. Here we report a cryo-electron microscopy (cryo-EM) structure of TRPC4 in its unliganded (apo) state to an overall resolution of 3.3 Å. The structure reveals a unique architecture with a long pore loop stabilized by a disulfide bond. Beyond the shared tetrameric six-transmembrane fold, the TRPC4 structure deviates from other TRP channels with a unique cytosolic domain. This unique cytosolic N-terminal domain forms extensive aromatic contacts with the TRP and the C-terminal domains. The comparison of our structure with other known TRP structures provides molecular insights into TRPC4 ion selectivity and extends our knowledge of the diversity and evolution of the TRP channels.
TRPS1 shapes YAP/TEAD-dependent transcription in breast cancer cells
Authors: Elster Dana , Tollot Marie , Schlegelmilch Karin , Ori Alessandro , Rosenwald Andreas , Sahai Erik , von Eyss Björn 
Published: July 2018

AbstractYes-associated protein (YAP), the downstream transducer of the Hippo pathway, is a key regulator of organ size, differentiation and tumorigenesis. To uncover Hippo-independent YAP regulators, we performed a genome-wide CRISPR screen that identifies the transcriptional repressor protein Trichorhinophalangeal Syndrome 1 (TRPS1) as a potent repressor of YAP-dependent transactivation. We show that TRPS1 globally regulates YAP-dependent transcription by binding to a large set of joint genomic sites, mainly enhancers. TRPS1 represses YAP-dependent function by recruiting a spectrum of corepressor complexes to joint sites. Loss of TRPS1 leads to activation of enhancers due to increased H3K27 acetylation and an altered promoter–enhancer interaction landscape. TRPS1 is commonly amplified in breast cancer, which suggests that restrained YAP activity favours tumour growth. High TRPS1 activity is associated with decreased YAP activity and leads to decreased frequency of tumour-infiltrating immune cells. Our study uncovers TRPS1 as an epigenetic regulator of YAP activity in breast cancer.
Nonequilibrium self-assembly dynamics of icosahedral viral capsids packaging genome or polyelectrolyte
Authors: Chevreuil Maelenn , Law-Hine Didier , Chen Jingzhi , Bressanelli Stéphane , Combet Sophie , Constantin Doru , Degrouard Jéril , Möller Johannes , Zeghal Mehdi , Tresset Guillaume 
Published: July 2018

AbstractThe survival of viruses partly relies on their ability to self-assemble inside host cells. Although coarse-grained simulations have identified different pathways leading to assembled virions from their components, experimental evidence is severely lacking. Here, we use time-resolved small-angle X-ray scattering to uncover the nonequilibrium self-assembly dynamics of icosahedral viral capsids packaging their full RNA genome. We reveal the formation of amorphous complexes via an en masse pathway and their relaxation into virions via a synchronous pathway. The binding energy of capsid subunits on the genome is moderate (~7kBT0, with kB the Boltzmann constant and T0 = 298 K, the room temperature), while the energy barrier separating the complexes and the virions is high (~ 20kBT0). A synthetic polyelectrolyte can lower this barrier so that filled capsids are formed in conditions where virions cannot build up. We propose a representation of the dynamics on a free energy landscape.
Biosensor libraries harness large classes of binding domains for construction of allosteric transcriptional regulators
Authors: Juárez Javier F. , Lecube-Azpeitia Begoña , Brown Stuart L. , Johnston Christopher D. , Church George M. 
Published: July 2018

AbstractThe ability of bacteria to sense specific molecules within their environment and trigger metabolic responses in accordance is an invaluable biotechnological resource. While many transcription factors (TFs) mediating such processes have been studied, only a handful have been leveraged for molecular biology applications. To expand the repertoire of biotechnologically relevant sensors we present a strategy for the construction and testing of chimeric TF libraries, based on the fusion of highly soluble periplasmic binding proteins (PBPs) with DNA-binding domains (DBDs). We validate this concept by constructing and functionally testing two unique sense-and-respond regulators for benzoate, an environmentally and industrially relevant metabolite. This work will enable the development of tailored biosensors for novel synthetic regulatory circuits.
Development of MPFC function mediates shifts in self-protective behavior provoked by social feedback
Authors: Yoon Leehyun , Somerville Leah H. , Kim Hackjin 
Published: July 2018

AbstractHow do people protect themselves in response to negative social feedback from others? How does such a self-protective system develop and affect social decisions? Here, using a novel reciprocal artwork evaluation task, we demonstrate that youths show self-protective bias based on current negative social evaluation, whereas into early adulthood, individuals show self-protective bias based on accumulated evidence of negative social evaluation. While the ventromedial prefrontal cortex (VMPFC) mediates self-defensive behavior based on both current and accumulated feedback, the rostromedial prefrontal cortex (RMPFC) exclusively mediates self-defensive behavior based on longer feedback history. Further analysis using a reinforcement learning model suggests that RMPFC extending into VMPFC, together with posterior parietal cortex (PPC), contribute to age-related increases in self-protection bias with deep feedback integration by computing the discrepancy between current feedback and previously estimated value of self-protection. These findings indicate that the development of RMPFC function is critical for sophisticated self-protective decisions.
Prevalence and patterns of higher-order drug interactions in Escherichia coli
Authors: Tekin Elif , White Cynthia , Kang Tina Manzhu , Singh Nina , Cruz-Loya Mauricio , Damoiseaux Robert , Savage Van M. , Yeh Pamela J. 
Published: July 2018

AbstractInteractions and emergent processes are essential for research on complex systems involving many components. Most studies focus solely on pairwise interactions and ignore higher-order interactions among three or more components. To gain deeper insights into higher-order interactions and complex environments, we study antibiotic combinations applied to pathogenic Escherichia coli and obtain unprecedented amounts of detailed data (251 two-drug combinations, 1512 three-drug combinations, 5670 four-drug combinations, and 13608 five-drug combinations). Directly opposite to previous assumptions and reports, we find higher-order interactions increase in frequency with the number of drugs in the bacteria’s environment. Specifically, as more drugs are added, we observe an elevated frequency of net synergy (effect greater than expected based on independent individual effects) and also increased instances of emergent antagonism (effect less than expected based on lower-order interaction effects). These findings have implications for the potential efficacy of drug combinations and are crucial for better navigating problems associated with the combinatorial complexity of multi-component systems.
Reductions in Retrieval Competition Predict the Benefit of Repeated Testing
Authors: Rafidi Nicole S. , Hulbert Justin C. , Brooks Paula P. , Norman Kenneth A. 
Published: July 2018

AbstractRepeated testing leads to improved long-term memory retention compared to repeated study, but the mechanism underlying this improvement remains controversial. In this work, we test the hypothesis that retrieval practice benefits subsequent recall by reducing competition from related memories. This hypothesis implies that the degree of reduction in competition between retrieval practice attempts should predict subsequent memory for practiced items. To test this prediction, we collected electroencephalography (EEG) data across two sessions. In the first session, participants practiced selectively retrieving exemplars from superordinate semantic categories (high competition), as well as retrieving the names of the superordinate categories from exemplars (low competition). In the second session, participants repeatedly studied and were tested on Swahili-English vocabulary. One week after session two, participants were again tested on the vocabulary. We trained a within-subject classifier on the data from session one to distinguish high and low competition states. We then used this classifier to measure the change in competition across multiple successful retrieval practice attempts in the second session. The degree to which competition decreased for a given vocabulary word predicted whether it was subsequently remembered in the third session. These results are consistent with the hypothesis that repeated testing improves retention by reducing competition.
Novel multifunctional RKKY coupling layer for ultrathin perpendicular synthetic antiferromagnet
Authors: Chatterjee Jyotirmoy , Auffret Stephane , Sousa Ricardo , Coelho Paulo , Prejbeanu Ioan-Lucian , Dieny Bernard 
Published: July 2018

AbstractA novel multi-functional antiferromagnetic coupling layer (MF-AFC) combining Ru and W is revealed to realize an extremely thin (3.8 nm), back-end-of-line compatible as well as magnetically and electrically stable perpendicular synthetic antiferromagnetic layer (pSAF), essential for spintronic memory and logic device applications. In addition to achieving antiferromagnetic RKKY coupling, this MF-AFC also acts as a Boron sink and texture-breaking layer. A detailed optimization of the thickness of the various involved layers has been carried out to obtain extremely thin-pSAF reference layer with stable magnetic properties, which enables the realization of sub-20 nm STT-MRAM cells. Two important advantages are provided by this ultrathin reference layer: the easing of the reference layer etching and the minimization of the dipolar field acting on the storage layer magnetization.
Hydra Mesoglea Proteome Identifies Thrombospondin as a Conserved Component Active in Head Organizer Restriction
Authors: Lommel Mark , Strompen Jennifer , Hellewell Andrew L. , Balasubramanian Gnana Prakash , Christofidou Elena D. , Thomson Andrew R. , Boyle Aimee L. , Woolfson Derek N. , Puglisi Kane , Hartl Markus , Holstein Thomas W. , Adams Josephine C. , Özbek Suat 
Published: July 2018

AbstractThrombospondins (TSPs) are multidomain glycoproteins with complex matricellular functions in tissue homeostasis and remodeling. We describe a novel role of TSP as a Wnt signaling target in the basal eumetazoan Hydra. Proteome analysis identified Hydra magnipapillata TSP (HmTSP) as a major component of the cnidarian mesoglea. In general, the domain organization of cnidarian TSPs is related to the pentameric TSPs of bilaterians, and in phylogenetic analyses cnidarian TSPs formed a separate clade of high sequence diversity. HmTSP expression in polyps was restricted to the hypostomal tip and tentacle bases that harbor Wnt-regulated organizer tissues. In the hypostome, HmTSP- and Wnt3-expressing cells were identical or in close vicinity to each other, and regions of ectopic tentacle formation induced by pharmacological β-Catenin activation (Alsterpaullone) corresponded to foci of HmTSP expression. Chromatin immunoprecipitation (ChIP) confirmed binding of Hydra TCF to conserved elements in the HmTSP promotor region. Accordingly, β-Catenin knockdown by siRNAs reduced normal HmTSP expression at the head organizer. In contrast, knockdown of HmTSP expression led to increased numbers of ectopic organizers in Alsterpaullone-treated animals, indicating a negative regulatory function. Our data suggest an unexpected role for HmTSP as a feedback inhibitor of Wnt signaling during Hydra body axis patterning and maintenance.
Lack of frequency-tagged magnetic responses suggests statistical regularities remain undetected during NREM sleep
Authors: Farthouat Juliane , Atas Anne , Wens Vincent , De Tiege Xavier , Peigneux Philippe 
Published: July 2018

AbstractHypnopedia, or the capacity to learn during sleep, is debatable. De novo acquisition of reflex stimulus-response associations was shown possible both in man and animal. Whether sleep allows more sophisticated forms of learning remains unclear. We recorded during diurnal Non-Rapid Eye Movement (NREM) sleep auditory magnetoencephalographic (MEG) frequency-tagged responses mirroring ongoing statistical learning. While in NREM sleep, participants were exposed at non-awakenings thresholds to fast auditory streams of pure tones, either randomly organized or structured in such a way that the stream statistically segmented in sets of 3 elements (tritones). During NREM sleep, only tone-related frequency-tagged MEG responses were observed, evidencing successful perception of individual tones. No participant showed tritone-related frequency-tagged responses, suggesting lack of segmentation. In the ensuing wake period however, all participants exhibited robust tritone-related responses during exposure to statistical (but not random) streams. Our data suggest that associations embedded in statistical regularities remain undetected during NREM sleep, although implicitly learned during subsequent wakefulness. These results suggest intrinsic limitations in de novo learning during NREM sleep that might confine the NREM sleeping brain’s learning capabilities to simple, elementary associations. It remains to be ascertained whether it similarly applies to REM sleep.
New Insight for Surface Chemistries in Ultra-thin Self-assembled Monolayers Modified High-voltage Spinel Cathodes
Authors: Kim Dae-wook , Uchida Shuhei , Shiiba Hiromasa , Zettsu Nobuyuki , Teshima Katsuya 
Published: July 2018

AbstractThe electrochemical properties of the interface between the spinel LiNi0.5Mn1.5O4-δ (LNMO4-δ) cathodes and ethylene carbonate−dimethyl carbonate (EC-DMC) electrolyte containing 1 M of LiPF6 have been investigated to achieve high-voltage durability of LNMO4-δ/graphite full cells. Coating the LNMO4-δ crystal surface by a fluoroalkylsilane self-assembled monolayer with a thickness below 2 nm resulted in a capacity retention of 94% after 100 cycles at a rate of 1 C and suppression of capacity fading for both the cathode and anode of the full cell. The observed effect is likely caused by the inhibited oxidative decomposition of EC−DMC electrolyte and vinylene carbonate (VC) species at the LNMO4-δ crystal surface and formation of a stable VC solid electrolyte interface near the anode. Moreover, the results obtained via photoelectron spectroscopy and density-functional calculations revealed that the increase in the work function of the LNMO4-δ crystal surface due to the formation of Si−O−Mn species primary contributed to the inhibition of the oxidative decomposition of the electrolyte and VC molecules at the cathode/electrolyte interface.
Characterization of Der f 22 - a paralogue of the major allergen Der f 2
Authors: Reginald Kavita , Tan Chye Ling , Chen Simin , Yuen Liling , Goh Sock Yong , Chew Fook Tim 
Published: July 2018

AbstractWe previously identified an expressed sequence tag clone, Der f 22, showing 41% amino acid identity to published Der f 2, and show that both genes are possible paralogues. The objective of this study was to characterize the genomic, proteomic and immunological functions Der f 22 and Der f 2. The full-length sequence of Der f 2 and Der f 22 coded for mature proteins of 129 and 135 amino acids respectively, both containing 6 cysteine residues. Phylogenetic analysis of known group 2 allergens and their homologues from our expressed sequence tag library showed that Der f 22 is a paralogue of Der f 2. Both Der f 2 and Der f 22 were single gene products with one intron. Both allergens showed specific IgE-binding to over 40% of the atopic patients, with limited of cross-reactivity. Both allergens were detected at the gut region of D. farinae by immunostaining. Der f 22 is an important allergen with significant IgE reactivity among the atopic population, and should be considered in the diagnostic panel and evaluated as future hypoallergen vaccine therapeutic target.
Mechanical ventilation and Streptococcus pneumoniae pneumonia alter mitochondrial homeostasis
Authors: Blot Mathieu , Pauchard Laure-Anne , Dunn Irène , Donze Jennifer , Malnuit Stéphanie , Rebaud Chloé , Croisier Delphine , Piroth Lionel , Pugin Jérôme , Charles Pierre-Emmanuel 
Published: July 2018

AbstractRequired mechanical ventilation (MV) may contribute to bacterial dissemination in patients with Streptococcus pneumoniae pneumonia. Significant variations in plasma mitochondrial DNA (mtDNA) have been reported in sepsis according to the outcome. The impact of lung stretch during MV was addressed in a model of pneumonia. Healthy or S. pneumoniae infected rabbits were submitted to MV or kept spontaneously breathing (SB). Bacterial burden, cytokines release, mitochondrial DNA levels, integrity and transcription were assessed along with 48-hour mortality. Compared with infected SB rabbits, MV rabbits developed more severe pneumonia with greater concentrations of bacteria in the lungs, higher rates of systemic dissemination, higher levels of circulating inflammatory mediators and decreased survival. Pulmonary mtDNA levels were significantly lower in infected animals as compared to non-infected ones, whenever they were SB or MV. After a significant early drop, circulating mtDNA levels returned to baseline values in the infected SB rabbits, but remained low until death in the MV ones. Whole blood ex-vivo stimulation with Streptococcus pneumoniae resulted in a reduction of polymorphonuclear leukocytes mitochondrial density and plasma mtDNA concentrations. Thus, persistent mitochondrial depletion and dysfunction in the infected animals submitted to MV could account for their less efficient immune response against S. pneumoniae.