bluuebunny/crossref_metadata_2025 huggingface dataset:
Science Directions in a Post COP21 World of Transient Climate Change: Enabling Regional to Local Predictions in Support of Reliable Climate Information
Authors: Stammer D. , Bracco A. , Braconnot P. , Brasseur G. P. , Griffies S. M. , Hawkins E.
Published: October 2018

During recent decades, through theoretical considerations and analyses of observations and model simulations, the scientific community has fundamentally advanced our understanding of the coupled climate system, thereby establishing that humans affect the Earth's climate. Resulting from this remarkable accomplishment, the COP21 agreement marks a historic turning point for climate research by calling for actionable regional climate change information on time scales from seasonal to centuries for the benefit of humanity, as well as living and nonliving elements of the Earth environment. Out of the underlying United National Framework Convention on climate Change process, improving seamless regional climate forecast capabilities emerges as a key challenge for the international research community. Addressing it requires a multiscale approach to climate predictions. Here we offer a vision that emphasizes enhanced scientific understanding of regional to local climate processes as the foundation for progress. The scientific challenge is extreme due to the rich complexity of interactions and feedbacks between regional and global processes, each of which affects the global climate trajectory. To gain the necessary scientific insight and to turn it into actionable climate information require technical development, international coordination, and a close interaction between the science and stakeholder communities.
Brine Pools Emerge as a New Place to Search for Life on Mars
Authors: Kornei Katherine
Published: October 2018

Some pools of salty water on the Red Planet could contain enough dissolved oxygen for microorganisms and sponges to survive, new calculations suggest.
Magnetosheath Reconnection Before Magnetopause Reconnection Driven by Interplanetary Tangential Discontinuity: A Three‐Dimensional Global Hybrid Simulation With Oblique Interplanetary Magnetic Field
Authors: Guo Zhifang , Lin Yu , Wang Xueyi , Du Aimin
Published: October 2018

Terrestrial dayside dynamics associated with a southward turning, oblique interplanetary magnetic field (IMF) carried by an interplanetary tangential discontinuity (TD) is investigated by performing a three‐dimensional global‐scale hybrid simulation systematically for cases in which the incoming solar wind TD possesses various magnetic field rotation angles ΔΦ = 90° to 180° and half widths w = 2di0 to w = 30di0, where di0 is the ion inertial length in the solar wind. Overall, the TD is compressed while being transmitted into the magnetosheath, with different compression processes downstream of the quasi‐parallel (Q‐||) and quasi‐perpendicular (Q‐⊥) shocks. It is found that magnetosheath reconnection may take place downstream of both the Q‐|| and Q‐⊥ shocks due to interaction of the directional TD with the bow shock and magnetopause, but the existence of magnetosheath reconnection depends on w and ΔΦ. Magnetosheath flux ropes are formed through three‐dimensional patchy reconnection in the thinned current sheet, with a longer rope lengths under a larger ΔΦ. There exists a dawn‐dusk asymmetry in the spatial extent of the flux ropes, which becomes more significant as ΔΦ decreases. When ΔΦ decreases to 90°, no reconnection flux ropes are found. Magnetopause reconnection is initiated when the magnetic fluxes with a southward turning IMF (on the sunward side) reach the magnetopause, and the magnetopause flux ropes can be mixed with the magnetosheath ones. Our simulation demonstrates that the effects of a southward turning of the IMF may not be a simple field direction change that leads to reconnection only at the magnetopause.
Models of the Formation of the 29 February 2016 New Spatter Cone Inside Mount Nyiragongo
Authors: Burgi P.‐Y. , Minissale S. , Melluso L. , Mahinda C. K. , Cuoco E. , Tedesco D.
Published: October 2018

A new and unusual eruptive event occurred on 29 February 2016 within the summit crater of the Mount Nyiragongo volcano. Based on field campaigns performed between July 2015 and September 2017, and building on a previously published buoyancy‐driven bidirectional magma flow model explaining the progression of Mount Nyiragongo lava lake level, we provide the first quantitative estimations of volumes of erupted lava outpouring from the new spatter cone. Besides matching field data of the lava lake level covering the period December 2002 to September 2017, numerical solutions of the model reveal that the most probable dike path is one originating from the shallow magma reservoir, and not from the lava lake or branching from its feeding conduit. According to these simulations, the reservoir and erupted lava volumes are respectively estimated to the order of 10 km3 and 20 M m3. Magma overpressure at the level of the shallow reservoir is estimated in the range 12 to 16 MPa, high enough to potentially initiate new erupting events.
Shallow Temporal Changes in S Wave Velocity and Polarization Anisotropy Associated With the 2016 Kumamoto Earthquake Sequence, Japan
Authors: Sawazaki Kaoru , Saito Tatsuhiko , Shiomi Katsuhiko
Published: October 2018

Applying deconvolution interferometry technique to surface‐borehole (down to 300 m) seismogram pairs of KiK‐net, we retrieved temporal changes in S wave velocities and polarization anisotropies associated with the 2016 Kumamoto earthquakes, Japan. The average S wave velocity decreased after the largest foreshock (Mw 6.2) and again after the Mw 7.0 mainshock, in the latter case, by as much as 6.4%. The seismic velocity susceptibility (SVS), defined as the ratio of the relative S wave velocity change to the maximum dynamic strain, ranged from −170 to −13. The absolute value of the SVS was larger at the sites near the ocean or covered by an embankment. Systematic changes were not observed for SVSs obtained after the largest foreshock and mainshock. At most sites, the average S wave velocity continued to recover for at least 1 year, proportional to the logarithm of the lapse time after the mainshock. The speed of the log‐time recovery (m‐value) appears to be independent of the maximum dynamic strain of the mainshock. Large m values were observed at the sites of large absolute SVS values, indicating that a more susceptible medium is more resilient. The strength of the S wave polarization anisotropy (anisotropy coefficient) increased by up to 0.8% after the mainshock, which was much smaller than the relative change in the average S wave velocity and was below the background change due to phenomena other than earthquakes. These observations can be explained qualitatively by considering fracture theory in a medium that contains many vertical cracks with randomly oriented polarizations.
Sizing of Ambient Particles From a Single‐Particle Soot Photometer Measurement to Retrieve Mixing State of Black Carbon at a Regional Site of the North China Plain
Authors: Zhang Yuxuan , Su Hang , Ma Nan , Li Guo , Kecorius Simonas , Wang Zhibin , Hu Min , Zhu Tong , He Kebin , Wiedensohler Alfred , Zhang Qiang , Cheng Yafang
Published: October 2018

We measured the mixing state of refractory black carbon (rBC) particles using a single‐particle soot photometer (SP2) on 11–27 July 2013 at a polluted regional site (~60 km to the south of Beijing) of the North China Plain. To improve retrieval of rBC mixing state, we validate and optimize the optical size (Dopt,p) of ambient particles derived from SP2 and Mie calculation. By matching the retrieved Dopt,p with the measured mobility diameter, we retrieve the densities (~0.3–0.6 g/cm3) and refractive indices (from 1.21–0.21i to 1.42–0.42i) of rBC core for thinly coated BC particles at mobility size of 200–350 nm; the refractive index of non‐BC (or coating) materials is estimated as 1.42–0i. It is found that the leading‐edge‐only‐fit method of SP2 calculation can be used to retrieve Dopt,p at least up to ~600 nm for ambient BC‐containing particles, and it can successfully provide Dopt,p of ambient non‐BC particles only up to ~500 nm. During the measurement campaign, the aging rate from thinly coated (or bare) BC to thickly coated BC can reach up to ~21%/hr around noontime, indicating the fast coating of BC. The average coating thickness (CT) of BC‐containing particles (200–350 nm) is ~41–71 nm, with ~13–16 nm CT for thinly coated (or bare) BC particles and ~75–114 nm CT for thickly coated BC particles. The mixing state of rBC obtained in this study indicates fast aging process and strong light‐absorbing capacity of BC particles under the polluted conditions in the North China Plain.
A Numerical Study of Convective‐Scale Structures in the Outer Cores of Sheared Tropical Cyclones: 1. Updraft Traits in Different Vertical Wind Shear Magnitudes
Authors: Li Qingqing , Fang Qiaoxian
Published: October 2018

This study investigates the outer‐core convective‐scale updraft features of numerically simulated tropical cyclones under vertical wind shear of different magnitudes. Updrafts in the outer core were weighted in favor of downshear formation, and the increase in the shear value led to more short‐lived updrafts. The tops of detected updrafts tended to cluster at either 4‐ to 6‐km or 12‐ to 14‐km height. Downshear‐left updrafts mostly moved radially inward, and updrafts on the left side of the shear vector moved more rapidly azimuthally. Longer‐lived updrafts gained greater vertical mass fluxes during their life cycles, with those in strongly sheared tropical cyclones having larger vertical mass fluxes for the same updraft life span. The height of stronger vertical velocity in convective bursts decreased as shear increased, whereas larger vertical velocity within nonconvective‐burst cells held between 3 and 4 km. The values of several environmental parameters (such as the supercell composite parameter and the energy‐helicity index) associated with updrafts in the downshear‐left quadrant were larger than those in the downshear‐right quadrant for the weakly sheared tropical cyclone, whereas they became much larger in the downshear‐right quadrant for highly sheared vortices. There were no relationships between the parameters and updraft mean mass fluxes, so the use of these parameters for predicting the likelihood of updraft strength in tropical cyclones requires caution.
Biomass Burning Plumes in the Vicinity of the California Coast: Airborne Characterization of Physicochemical Properties, Heating Rates, and Spatiotemporal Features
Authors: Mardi Ali Hossein , Dadashazar Hossein , MacDonald Alexander B. , Braun Rachel A. , Crosbie Ewan , Xian Peng , Thorsen Tyler J. , Coggon Matthew M. , Fenn Marta A. , Ferrare Richard A. , Hair Johnathan W. , Woods Roy K. , Jonsson Haflidi H. , Flagan Richard C. , Seinfeld John H. , Sorooshian Armin
Published: October 2018

This study characterizes in situ airborne properties associated with biomass burning (BB) plumes in the vicinity of the California coast. Out of 231 total aircraft soundings in July–August 2013 and 2016, 81 were impacted by BB layers. A number of vertical characteristics of BB layers are summarized in this work (altitude, location relative to cloud top height, thickness, number of vertically adjacent layers, interlayer distances) in addition to differences in vertical aerosol concentration profiles due to either surface type (e.g., land or ocean) or time of day. Significant BB layer stratification occurred, especially over ocean versus land, with the majority of layers in the free troposphere and within 100 m of the boundary layer top. Heating rate profiles demonstrated the combined effect of cloud and BB layers and their mutual interactions, with enhanced heating in BB layers with clouds present underneath. Aerosol size distribution data are summarized below and above the boundary layer, with a notable finding being enhanced concentrations of supermicrometer particles in BB conditions. A plume aging case study revealed the dominance of organics in the free troposphere, with secondary production of inorganic and organic species and coagulation as a function of distance from fire source up to 450 km. Rather than higher horizontal and vertical resolution, a new smoke injection height method was the source of improved agreement for the vertical distribution of BB aerosol in the Navy Aerosol Analysis and Prediction System model when compared to airborne data.
Glacial Erosion Driven by Variations in Meltwater Drainage
Authors: Ugelvig S. V. , Egholm D. L. , Anderson R. S. , Iverson N. R.
Published: October 2018

The subglacial processes of abrasion and quarrying are thought to be primarily responsible for bedrock erosion by glaciers. While theory points to sliding speed as the dominant control on abrasion, rates of quarrying are likely scaled by a more complex combination of sliding speed, effective pressure, bed roughness, and short‐term water‐pressure fluctuations. Here we pair a model for quarrying based on statistical characterization of bedrock strength with a model for subglacial hydrology that describes the temporal evolution of cavities under the influence of variations in sliding speed and effective pressure. Using a finite element model, we simulate the evolution of the hydrological system at the base of a glacier and compute rates of abrasion and quarrying. Cavity lengths and channel cross sections evolve through time, causing temporal shifts in ice‐bed contact area, which in turn govern the differential stress that influences erosion over the course of a year. Our results demonstrate how variations in meltwater production amplify rates of subglacial erosion relative to the case of steady meltwater generation. The level of amplification depends on how the variations control the ice‐bed contact area. Seasonal variations are most effective in boosting mean rates of basal sliding and hence subglacial abrasion, whereas shorter‐term variations (monthly‐weekly) most strongly influence rates of subglacial quarrying through temporal amplification of differential bedrock stress around cavities. This influence of transient hydrology on subglacial erosion processes may explain why glaciers in temperate climates with strong variations in temperature and precipitation erode faster than similar‐type glaciers in polar environments.
MicroRNA-139-3p regulates osteoblast differentiation and apoptosis by targeting ELK1 and interacting with long noncoding RNA ODSM
Authors: Wang Yixuan , Wang Ke , Hu Zebing , Zhou Hua , Zhang Lijun , Wang Han , Li Gaozhi , Zhang Shu , Cao Xinsheng , Shi Fei
Published: October 2018

Recent studies have confirmed that microRNAs and lncRNAs can affect bone cell differentiation and bone formation. In this study, miR-139-3p was upregulated in the femurs of hindlimb unloading mice and MC3T3-E1 cells under simulated microgravity; this effect was related to osteoblast differentiation and apoptosis. Silencing miR-139-3p attenuated the suppression of differentiation and the promotion of MC3T3-E1 cell apoptosis induced by simulated microgravity. ELK1 is a target of miR-139-3p and is essential for miR-139-3p to regulate osteoblast differentiation and apoptosis. An osteoblast differentiation-related lncRNA that could interact with miR-139-3p (lncRNA ODSM) was identified in MC3T3-E1 cells under simulated microgravity. Further investigations demonstrated that lncRNA ODSM could promote MC3T3-E1 cell differentiation. Therefore, this research was the first to reveal the critical role of the lncRNA ODSM/miR-139-3p/ELK1 pathway in osteoblasts, and these findings suggest the potential value of miR-139-3p in osteoporosis diagnosis and therapy.
Dynamic laminar rerouting of inter-areal mnemonic signal by cognitive operations in primate temporal cortex
Authors: Takeda Masaki , Hirabayashi Toshiyuki , Adachi Yusuke , Miyashita Yasushi
Published: October 2018

Execution of cognitive functions is orchestrated by a brain-wide network comprising multiple regions. However, it remains elusive whether the cortical laminar pattern of inter-areal interactions exhibits dynamic routings, depending on cognitive operations. We address this issue by simultaneously recording neuronal activities from area 36 and area TE of the temporal cortex while monkeys performed a visual cued-recall task. We identify dynamic laminar routing of the inter-areal interaction: during visual processing of a presented cue, spiking activities of area 36 neurons are preferentially coherent with local field potentials at the supragranular layer of area TE, while the signal from the same neurons switches to target the infragranular layer of area TE during memory retrieval. This layer-dependent signal represents the to-be-recalled object, and has an impact on the local processing at the supragranular layer in both cognitive operations. Thus, cortical layers form a key structural basis for dynamic switching of cognitive operations.
A low-gluten diet induces changes in the intestinal microbiome of healthy Danish adults
Authors: Hansen Lea B. S. , Roager Henrik M. , Søndertoft Nadja B. , Gøbel Rikke J. , Kristensen Mette , Vallès-Colomer Mireia , Vieira-Silva Sara , Ibrügger Sabine , Lind Mads V. , Mærkedahl Rasmus B. , Bahl Martin I. , Madsen Mia L. , Havelund Jesper , Falony Gwen , Tetens Inge , Nielsen Trine , Allin Kristine H. , Frandsen Henrik L. , Hartmann Bolette , Holst Jens Juul , Sparholt Morten H. , Holck Jesper , Blennow Andreas , Moll Janne Marie , Meyer Anne S. , Hoppe Camilla , Poulsen Jørgen H. , Carvalho Vera , Sagnelli Domenico , Dalgaard Marlene D. , Christensen Anders F. , Lydolph Magnus Christian , Ross Alastair B. , Villas-Bôas Silas , Brix Susanne , Sicheritz-Pontén Thomas , Buschard Karsten , Linneberg Allan , Rumessen Jüri J. , Ekstrøm Claus T. , Ritz Christian , Kristiansen Karsten , Nielsen H. Bjørn , Vestergaard Henrik , Færgeman Nils J. , Raes Jeroen , Frøkiær Hanne , Hansen Torben , Lauritzen Lotte , Gupta Ramneek , Licht Tine Rask , Pedersen Oluf
Published: October 2018

Adherence to a low-gluten diet has become increasingly common in parts of the general population. However, the effects of reducing gluten-rich food items including wheat, barley and rye cereals in healthy adults are unclear. Here, we undertook a randomised, controlled, cross-over trial involving 60 middle-aged Danish adults without known disorders with two 8-week interventions comparing a low-gluten diet (2 g gluten per day) and a high-gluten diet (18 g gluten per day), separated by a washout period of at least six weeks with habitual diet (12 g gluten per day). We find that, in comparison with a high-gluten diet, a low-gluten diet induces moderate changes in the intestinal microbiome, reduces fasting and postprandial hydrogen exhalation, and leads to improvements in self-reported bloating. These observations suggest that most of the effects of a low-gluten diet in non-coeliac adults may be driven by qualitative changes in dietary fibres.
Roll-to-roll fabrication of touch-responsive cellulose photonic laminates
Authors: Liang Hsin-Ling , Bay Mélanie M. , Vadrucci Roberto , Barty-King Charles H. , Peng Jialong , Baumberg Jeremy J. , De Volder Michael F. L. , Vignolini Silvia
Published: October 2018

Hydroxypropyl-cellulose (HPC), a derivative of naturally abundant cellulose, can self-assemble into helical nanostructures that lead to striking colouration from Bragg reflections. The helical periodicity is very sensitive to pressure, rendering HPC a responsive photonic material. Recent advances in elucidating these HPC mechano-chromic properties have so-far delivered few real-world applications, which require both up-scaling fabrication and digital translation of their colour changes. Here we present roll-to-roll manufactured metre-scale HPC laminates using continuous coating and encapsulation. We quantify the pressure response of the encapsulated HPC using optical analyses of the pressure-induced hue change as perceived by the human eye and digital imaging. Finally, we show the ability to capture real-time pressure distributions and temporal evolution of a human foot-print on our HPC laminates. This is the first demonstration of a large area and cost-effective method for fabricating HPC stimuli-responsive photonic films, which can generate pressure maps that can be read out with standard cameras.
Author Correction: Gap junction protein Connexin-43 is a direct transcriptional regulator of N-cadherin in vivo
Authors: Kotini Maria , Barriga Elias H. , Leslie Jonathan , Gentzel Marc , Rauschenberger Verena , Schambony Alexandra , Mayor Roberto
Published: October 2018

The original version of this Article contained an error in the spelling of the author Alexandra Schambony, which was incorrectly given as Alexandra Schambon. This has now been corrected in both the PDF and HTML versions of the Article.
Touchscreen testing reveals clinically relevant cognitive abnormalities in a mouse model of schizophrenia lacking metabotropic glutamate receptor 5
Authors: Zeleznikow-Johnston Ariel M. , Renoir Thibault , Churilov Leonid , Li Shanshan , Burrows Emma L. , Hannan Anthony J.
Published: October 2018

Metabotropic glutamate receptor 5 (mGlu5) has been implicated in certain forms of synaptic plasticity and cognitive function. mGlu5 knockout (KO) mice and mGlu5 antagonists have been previously used to study the pathophysiology of schizophrenia as they have been shown respectively to display or induce endophenotypes relevant to schizophrenia. While schizophrenia presents with generalized cognitive impairments, the cognitive phenotype of mice lacking mGlu5 has so far only been explored using largely hippocampal-dependent spatial and contextual memory tasks. To address this, we used a touchscreen system to assess mGlu5 KO mice for pairwise visual discrimination, reversal learning, and extinction of an instrumental response requiring no discrimination. Furthermore, we tested the role of mGlu5 in working memory using the Trial-Unique Non-Matching to Location (TUNL) task utilizing pharmacological ablation. mGlu5 KO mice were impaired on discrimination learning, taking longer to reach criterion and requiring more correction learning trials. Performance on reversal learning was also impaired, with mGlu5 KO mice demonstrating a perseverative phenotype. The mGlu5 KO mice responded at a higher rate during extinction, consistent with this perseverative profile. In contrast, wildtype mice treated acutely with an mGlu5 antagonist (MTEP) showed no deficits in a touchscreen task assessing working memory. The present study demonstrates learning and memory deficits as well as an increased perseverative phenotype following constitutive loss of mGlu5 in this mouse model of schizophrenia. These findings will inform translational approaches using this preclinical model and the pursuit of mGlu5 as therapeutic target for schizophrenia and other brain disorders.
Ectopic beats arise from micro-reentries near infarct regions in simulations of a patient-specific heart model
Authors: Oliveira Rafael Sachetto , Alonso Sergio , Campos Fernando Otaviano , Rocha Bernardo Martins , Fernandes João Filipe , Kuehne Titus , dos Santos Rodrigo Weber
Published: October 2018

Ectopic beats are known to be involved in the initiation of a variety of cardiac arrhythmias. Although their location may vary, ectopic excitations have been found to originate from infarct areas, regions of micro-fibrosis and other heterogeneous tissues. However, the underlying mechanisms that link ectopic foci to heterogeneous tissues have yet to be fully understood. In this work, we investigate the mechanism of micro-reentry that leads to the generation of ectopic beats near infarct areas using a patient-specific heart model. The patient-specific geometrical model of the heart, including scar and peri-infarct zones, is obtained through magnetic resonance imaging (MRI). The infarct region is composed of ischemic myocytes and non-conducting cells (fibrosis, for instance). Electrophysiology is captured using an established cardiac myocyte model of the human ventricle modified to describe ischemia. The simulation results clearly reveal that ectopic beats emerge from micro-reentries that are sustained by the heterogeneous structure of the infarct regions. Because microscopic information about the heterogeneous structure of the infarct regions is not available, Monte-Carlo simulations are used to identify the probabilities of an infarct region to behave as an ectopic focus for different levels of ischemia and different percentages of non-conducting cells. From the proposed model, it is observed that ectopic beats are generated when a percentage of non-conducting cells is near a topological metric known as the percolation threshold. Although the mechanism for micro-reentries was proposed half a century ago to be a source of ectopic beats or premature ventricular contractions during myocardial infarction, the present study is the first to reproduce this mechanism in-silico using patient-specific data.
Metabolic pathways synthesis based on ant colony optimization
Authors: Gerard Matias F. , Stegmayer Georgina , Milone Diego H.
Published: October 2018

One of the current challenges in bioinformatics is to discover new ways to transform a set of compounds into specific products. The usual approach is finding the reactions to synthesize a particular product, from a given substrate, by means of classical searching algorithms. However, they have three main limitations: difficulty in handling large amounts of reactions and compounds; absence of a step that verifies the availability of substrates; and inability to find branched pathways. We present here a novel bio-inspired algorithm for synthesizing linear and branched metabolic pathways. It allows relating several compounds simultaneously, ensuring the availability of substrates for every reaction in the solution. Comparisons with classical searching algorithms and other recent metaheuristic approaches show clear advantages of this proposal, fully recovering well-known pathways. Furthermore, solutions found can be analyzed in a simple way through graphical representations on the web.
Linking Structure to Dynamics in Protic Ionic Liquids: A Neutron Scattering Study of Correlated and Single-Particle Motions
Authors: Burankova Tatsiana , Mora Cardozo Juan F. , Rauber Daniel , Wildes Andrew , Embs Jan P.
Published: October 2018

Coupling between dynamical heterogeneity of ionic liquids and their structural periodicity on different length-scales can be directly probed by quasielastic neutron scattering with polarization analysis. The technique provides the tools to investigate single-particle and cooperative ion motions separately and, thus, dynamics of ion associations affecting the net charge transport can be experimentally explored. The focus of this study is the structure-dynamic relationship in the protic ionic liquid, triethylammonium triflate, characterized by strong hydrogen bonds between cations and anions. The site-selective deuterium/hydrogen-isotope substitution was applied to modulate the relative contributions of different atom groups to the total coherent and incoherent scattering signal. This approach in combination with molecular dynamics simulations allowed us to obtain a sophisticated description of cation self-diffusion and confined ion pair dynamics from the incoherent spectral component by using the acidic proton as a tagged particle. The coherent contribution of the neutron spectra demonstrated substantial ion association leading to collective ion migration that preserves charge alteration on picosecond time scale, as well as correlation of the localized dynamics occurring between adjacent ions.
Accuracy-Precision Trade-off in Human Sound Localisation
Authors: Ege Rachel , Opstal A. John Van , Van Wanrooij Marc M.
Published: October 2018

Sensory representations are typically endowed with intrinsic noise, leading to variability and inaccuracies in perceptual responses. The Bayesian framework accounts for an optimal strategy to deal with sensory-motor uncertainty, by combining the noisy sensory input with prior information regarding the distribution of stimulus properties. The maximum-a-posteriori (MAP) estimate selects the perceptual response from the peak (mode) of the resulting posterior distribution that ensure optimal accuracy-precision trade-off when the underlying distributions are Gaussians (minimal mean-squared error, with minimum response variability). We tested this model on human eye- movement responses toward broadband sounds, masked by various levels of background noise, and for head movements to sounds with poor spectral content. We report that the response gain (accuracy) and variability (precision) of the elevation response components changed systematically with the signal-to-noise ratio of the target sound: gains were high for high SNRs and decreased for low SNRs. In contrast, the azimuth response components maintained high gains for all conditions, as predicted by maximum-likelihood estimation. However, we found that the elevation data did not follow the MAP prediction. Instead, results were better described by an alternative decision strategy, in which the response results from taking a random sample from the posterior in each trial. We discuss two potential implementations of a simple posterior sampling scheme in the auditory system that account for the results and argue that although the observed response strategies for azimuth and elevation are sub-optimal with respect to their variability, it allows the auditory system to actively explore the environment in the absence of adequate sensory evidence.
Thin Film Multi-Electrode Softening Cuffs for Selective Neuromodulation
Authors: González-González María A. , Kanneganti Aswini , Joshi-Imre Alexandra , Hernandez-Reynoso Ana G. , Bendale Geetanjali , Modi Romil , Ecker Melanie , Khurram Ali , Cogan Stuart F. , Voit Walter E. , Romero-Ortega Mario I.
Published: October 2018

Silicone nerve cuff electrodes are commonly implanted on relatively large and accessible somatic nerves as peripheral neural interfaces. While these cuff electrodes are soft (1–50 MPa), their self-closing mechanism requires of thick walls (200–600 µm), which in turn contribute to fibrotic tissue growth around and inside the device, compromising the neural interface. We report the use of thiol-ene/acrylate shape memory polymer (SMP) for the fabrication of thin film multi-electrode softening cuffs (MSC). We fabricated multi-size MSC with eight titanium nitride (TiN) electrodes ranging from 1.35 to 13.95 × 10−4 cm2 (1–3 kΩ) and eight smaller gold (Au) electrodes (3.3 × 10−5 cm2; 750 kΩ), that soften at physiological conditions to a modulus of 550 MPa. While the SMP material is not as soft as silicone, the flexural forces of the SMP cuff are about 70–700 times lower in the MSC devices due to the 30 μm thick film compared to the 600 μm thick walls of the silicone cuffs. We demonstrated the efficacy of the MSC to record neural signals from rat sciatic and pelvic nerves (1000 µm and 200 µm diameter, respectively), and the selective fascicular stimulation by current steering. When implanted side-by-side and histologically compared 30 days thereafter, the MSC devices showed significantly less inflammation, indicated by a 70–80% reduction in ED1 positive macrophages, and 54–56% less fibrotic vimentin immunoreactivity. Together, the data supports the use of MSC as compliant and adaptable technology for the interfacing of somatic and autonomic peripheral nerves.
Integrative bioinformatics identifies postnatal lead (Pb) exposure disrupts developmental cortical plasticity
Authors: Smith Milo R. , Yevoo Priscilla , Sadahiro Masato , Austin Christine , Amarasiriwardena Chitra , Awawda Mahmoud , Arora Manish , Dudley Joel T. , Morishita Hirofumi
Published: October 2018

Given that thousands of chemicals released into the environment have the potential capacity to harm neurodevelopment, there is an urgent need to systematically evaluate their toxicity. Neurodevelopment is marked by critical periods of plasticity wherein neural circuits are refined by the environment to optimize behavior and function. If chemicals perturb these critical periods, neurodevelopment can be permanently altered. Focusing on 214 human neurotoxicants, we applied an integrative bioinformatics approach using publically available data to identify dozens of neurotoxicant signatures that disrupt a transcriptional signature of a critical period for brain plasticity. This identified lead (Pb) as a critical period neurotoxicant and we confirmed in vivo that Pb partially suppresses critical period plasticity at a time point analogous to exposure associated with autism. This work demonstrates the utility of a novel informatics approach to systematically identify neurotoxicants that disrupt childhood neurodevelopment and can be extended to assess other environmental chemicals.
An Electroencephalography Bioassay for Preclinical Testing of Analgesic Efficacy
Authors: Koyama Suguru , LeBlanc Brian W. , Smith Kelsey A. , Roach Catherine , Levitt Joshua , Edhi Muhammad M. , Michishita Mai , Komatsu Takayuki , Mashita Okishi , Tanikawa Aki , Yoshikawa Satoru , Saab Carl Y.
Published: October 2018

We present a multimodal method combining quantitative electroencephalography (EEG), behavior and pharmacology for pre-clinical screening of analgesic efficacy in vivo. The method consists of an objective and non-invasive approach for realtime assessment of spontaneous nociceptive states based on EEG recordings of theta power over primary somatosensory cortex in awake rats. Three drugs were chosen: (1) pregabalin, a CNS-acting calcium channel inhibitor; (2) EMA 401, a PNS-acting angiotensin II type 2 receptor inhibitor; and (3) minocycline, a CNS-acting glial inhibitor. Optimal doses were determined based on pharmacokinetic studies and/or published data. The effects of these drugs at single or multiple doses were tested on the attenuation of theta power and paw withdrawal latency (PWL) in a rat model of neuropathic pain. We report mostly parallel trends in the reversal of theta power and PWL in response to administration of pregabalin and EMA 401, but not minocycline. We also note divergent trends at non-optimal doses and following prolonged drug administration, suggesting that EEG theta power can be used to detect false positive and false negative outcomes of the withdrawal reflex behavior, and yielding novel insights into the analgesic effects of these drugs on spontaneous nociceptive states in rats.
AII amacrine cells in the primate fovea contribute to photopic vision
Authors: Strettoi Enrica , Masri Rania A. , Grünert Ulrike
Published: October 2018

The AII amacrine cell is known as a key interneuron in the scotopic (night-vision) pathway in the retina. Under scotopic conditions, rod signals are transmitted via rod bipolar cells to AII amacrine cells, which split the rod signal into the OFF (via glycinergic synapses) and the ON pathway (via gap junctions). But the AII amacrine cell also has a “day job”: at high light levels when cones are active, AII connections with ON cone bipolar cells provide crossover inhibition to extend the response range of OFF cone bipolar cells. The question whether AII cells contribute to crossover inhibition in primate fovea (where rods and rod bipolar cells are rare or absent) has not been answered. Here, immunohistochemistry and three-dimensional reconstruction show that calretinin positive cells in the fovea of macaque monkeys and humans have AII morphology and connect to cone bipolar cells. The pattern of AII connections to cone bipolar cells is quantitatively similar to that of AII cells outside the fovea. Our results support the view that in mammalian retina AII cells first evolved to serve cone circuits, then later were co-opted to process scotopic signals subsequent to the evolution of rod bipolar cells.
Gene set enrichment analysis of the bronchial epithelium implicates contribution of cell cycle and tissue repair processes in equine asthma
Authors: Tessier Laurence , Côté Olivier , Clark Mary Ellen , Viel Laurent , Diaz-Méndez Andrés , Anders Simon , Bienzle Dorothee
Published: October 2018

Severe equine asthma is a chronic inflammatory condition of the lower airways similar to adult-onset asthma in humans. Exacerbations are characterized by bronchial and bronchiolar neutrophilic inflammation, mucus hypersecretion and airway constriction. In this study we analyzed the gene expression response of the bronchial epithelium within groups of asthmatic and non-asthmatic animals following exposure to a dusty hay challenge. After challenge we identified 2341 and 120 differentially expressed genes in asthmatic and non-asthmatic horses, respectively. Gene set enrichment analysis of changes in gene expression after challenge identified 587 and 171 significantly enriched gene sets in asthmatic and non-asthmatic horses, respectively. Gene sets in asthmatic animals pertained, but were not limited, to cell cycle, neutrophil migration and chemotaxis, wound healing, hemostasis, coagulation, regulation of body fluid levels, and the hedgehog pathway. Furthermore, transcription factor target enrichment analysis in the asthmatic group showed that transcription factor motifs with the highest enrichment scores for up-regulated genes belonged to the E2F transcription factor family. It is postulated that engagement of hedgehog and E2F pathways in asthmatic horses promotes dysregulated cell proliferation and abnormal epithelial repair. These fundamental lesions may prevent re-establishment of homeostasis and perpetuate inflammation.
Integration of visual and whisker signals in rat superior colliculus
Authors: Gharaei Saba , Arabzadeh Ehsan , Solomon Samuel G.
Published: October 2018

Multisensory integration is a process by which signals from different sensory modalities are combined to facilitate detection and localization of external events. One substrate for multisensory integration is the midbrain superior colliculus (SC) which plays an important role in orienting behavior. In rodent SC, visual and somatosensory (whisker) representations are in approximate registration, but whether and how these signals interact is unclear. We measured spiking activity in SC of anesthetized hooded rats, during presentation of visual- and whisker stimuli that were tested simultaneously or in isolation. Visual responses were found in all layers, but were primarily located in superficial layers. Whisker responsive sites were primarily found in intermediate layers. In single- and multi-unit recording sites, spiking activity was usually only sensitive to one modality, when stimuli were presented in isolation. By contrast, we observed robust and primarily suppressive interactions when stimuli were presented simultaneously to both modalities. We conclude that while visual and whisker representations in SC of rat are partially overlapping, there is limited excitatory convergence onto individual sites. Multimodal integration may instead rely on suppressive interactions between modalities.
Understanding the role of bitter taste perception in coffee, tea and alcohol consumption through Mendelian randomization
Authors: Ong Jue-Sheng , Hwang Liang-Dar , Zhong Victor W. , An Jiyuan , Gharahkhani Puya , Breslin Paul A. S. , Wright Margaret J. , Lawlor Deborah A. , Whitfield John , MacGregor Stuart , Martin Nicholas G. , Cornelis Marilyn C.
Published: October 2018

Consumption of coffee, tea and alcohol might be shaped by individual differences in bitter taste perception but inconsistent observational findings provide little insight regarding causality. We conducted Mendelian randomization analyses using genetic variants associated with the perception of bitter substances (rs1726866 for propylthiouracil [PROP], rs10772420 for quinine and rs2597979 for caffeine) to evaluate the intake of coffee, tea and alcohol among up to 438,870 UK Biobank participants. A standard deviation (SD) higher in genetically predicted bitterness of caffeine was associated with increased coffee intake (0.146 [95%CI: 0.103, 0.189] cups/day), whereas a SD higher in those of PROP and quinine was associated with decreased coffee intake (−0.021 [−0.031, −0.011] and −0.081 [−0.108, −0.054] cups/day respectively). Higher caffeine perception was also associated with increased risk of being a heavy (>4 cups/day) coffee drinker (OR 1.207 [1.126, 1.294]). Opposite pattern of associations was observed for tea possibly due to the inverse relationship between both beverages. Alcohol intake was only negatively associated with PROP perception (−0.141 [−1.88, −0.94] times/month per SD increase in PROP bitterness). Our results reveal that bitter perception is causally associated with intake of coffee, tea and alcohol, suggesting a role of bitter taste in the development of bitter beverage consumption.
Author Correction: Revelation of early detection of co-seismic ionospheric perturbations in GPS-TEC from realistic modelling approach: Case study
Authors: Thomas Dhanya , Bagiya Mala S. , Sunil Poikayil Sukumaran , Rolland Lucie , Sunil Anakuzhikkal Sudarsanan , Mikesell T. Dylan , Nayak Srinivas , Mangalampalli Subrahmanyam , Ramesh Durbha Sai
Published: October 2018

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.
Super-resolution imaging using nano-bells
Authors: Fuentes-Domínguez Rafael , Pérez-Cota Fernando , Naznin Shakila , Smith Richard J. , Clark Matt
Published: October 2018

In this paper we demonstrate a new scheme for optical super-resolution, inspired, in-part, by PALM and STORM. In this scheme each object in the field of view is tagged with a signal that allows them to be detected separately. By doing this we can identify and locate each object separately with significantly higher resolution than the diffraction limit. We demonstrate this by imaging nanoparticles significantly smaller than the optical resolution limit. In this case the “tag” we have used is the frequency of vibration of nanoscale “bells” made of metallic nanoparticles whose acoustic vibrational frequency is in the multi-GHz range. Since the vibration of the particles can be easily excited and detected and the frequency is directly related to the particle size, we can separate the signals from many particles of sufficiently different sizes even though they are smaller than, and separated by less than, the optical resolution limit. Using this scheme we have been able to localise the nanoparticle position with a precision of ~3 nm. This has many potential advantages - such nanoparticles are easily inserted into cells and well tolerated, the particles do not bleach and can be produced easily with very dispersed sizes. We estimate that 50 or more different particles (or frequency channels) can be accessed in each optical point spread function using the vibrational frequencies of gold nanospheres. However, many more channels may be accessed using more complex structures (such as nanorods) and detection techniques (for instance using polarization or wavelength selective detection) opening up this technique as a generalized method of achieving super-optical resolution imaging.
First Precambrian palaeomagnetic data from the Mawson Craton (East Antarctica) and tectonic implications
Authors: Liu Yebo , Li Zheng-Xiang , Pisarevsky Sergei A. , Kirscher Uwe , Mitchell Ross N. , Stark J. Camilla , Clark Chris , Hand Martin
Published: October 2018

A pilot palaeomagnetic study was conducted on the recently dated with in situ SHRIMP U-Pb method at 1134 ± 9 Ma (U-Pb, zircon and baddeleyite) Bunger Hills dykes of the Mawson Craton (East Antarctica). Of the six dykes sampled, three revealed meaningful results providing the first well-dated Mesoproterozoic palaeopole at 40.5°S, 150.1°E (A95 = 20°) for the Mawson Craton. Discordance between this new pole and two roughly coeval poles from Dronning Maud Land and Coats Land (East Antarctica) demonstrates that these two terranes were not rigidly connected to the Mawson Craton ca. 1134 Ma. Comparison between the new pole and that of the broadly coeval Lakeview dolerite from the North Australian Craton supports the putative ~40° late Neoproterozoic relative rotation between the North Australian Craton and the combined South and West Australian cratons. A mean ca. 1134 Ma pole for the Proto-Australia Craton is calculated by combining our new pole and that of the Lakeview dolerite after restoring the 40° intracontinental rotation. A comparison of this mean pole with the roughly coeval Abitibi dykes pole from Laurentia confirms that the SWEAT reconstruction of Australia and Laurentia was not viable for ca. 1134 Ma.
Ultrafast soliton and stretched-pulse switchable mode-locked fiber laser with hybrid structure of multimode fiber based saturable absorber
Authors: Zhao Fengyan , Wang Yishan , Wang Hushan , Yan Zhijun , Hu Xiaohong , Zhang Wei , Zhang Ting , Zhou Kaiming
Published: October 2018

We demonstrate an all-fiber mode locked laser based on hybrid structure of multimode fiber saturable absorber (SA) that can realize both conventional soliton and stretched-pulse states. Stable 16.44 MHz conventional soliton pulses are achieved by injecting 80 mW threshold pump power. By increasing the incident pump power to 420 mW, the laser evolves from soliton operation into stretched-pulse mode locking state. 310 fs stretched-pulse are obtained with the same repetition rate as the soliton pulses. The center wavelength and its 3 dB spectrum bandwidth are 1603 nm and 14.2 nm, respectively. For the first time, we experimentally confirm transition between conventional soliton and stretched-pulse in 1.5 μm mode-locked fiber laser by introducing multimode optical fiber SA. Moreover, the maximum single pulse energy of nearly 1 nJ is achieved. Such all-fiber mode-locked lasers based on hybrid structure of multimode fiber are attractive for practical applications without damage and the limitation of life time.
The arrangement of lateral veins along the midvein of leaves is not related to leaf phyllotaxis
Authors: Koyama Kohei , Masuda Teruhisa
Published: October 2018

Positions of leaves along a stem usually adhere to a genetically determined, species-specific pattern known as a leaf phyllotaxis. We investigated whether the arrangement of lateral secondary veins along primary midveins adhered to a species-specific pattern that resembled an alternate or opposite phyllotaxis. We analyzed the venation of temperate dicotyledonous species from different taxonomic groups and chose 18 woody and 12 herbaceous species that have reticulated leaf venation. The arrangement of the lateral veins was neither alternate nor opposite for any of the species. Lateral vein arrangements were instead mixtures of symmetric and asymmetric patterns. Our results show that lateral vein arrangements are related neither to stem-level leaf phyllotaxis (alternate vs. opposite) nor to life form (woody vs. herbaceous). Our results are therefore generally consistent with the canalization hypothesis that the locations of lateral veins are not completely specified genetically prior to leaf formation.