bluuebunny/crossref_metadata_2025 huggingface dataset:
Ubiquitous millimeter-wavelength Class I methanol masers associated with massive (proto)stellar outflows: ALMA and SMA results
Authors: Cyganowski C. J. , Hannaway D. , Brogan C. L. , Hunter T. R. , Zhang Q.
Published: July 2018

We report the discovery of widespread millimeter-wavelength Class I methanol maser emission associated with protostellar molecular outflows in the massive (proto)cluster G11.92−0.61. Our ~0.5″-resolution SMA and ALMA observations of the 229 GHz and 278 GHz Class I transitions reveal seven and twelve candidate masers, respectively: all 229 GHz masers have 278 GHz counterparts, and five are also coincident with 44 GHz Class I masers previously detected with the VLA. For paired masers, the peak intensities at 229 GHz and 278 GHz are correlated. We also find tentative evidence for a correlation between the strength of millimeter-wavelength Class I maser emission and the energy of the associated molecular outflow.
H2O MegaMasers: RadioAstron success story
Authors: Baan Willem , Alakoz Alexey , An Tao , Ellingsen Simon , Henkel Christian , Imai Hiroshi , Kostenko Vladimir , Litovchenko Ivan , Moran James , Sobolev Andrej , Tolmachev Alexander
Published: July 2018

The RadioAstron space-VLBI mission has successfully detected extragalactic H2O MegaMaser emission regions at very long Earth to space baselines ranging between 1.4 and 26.7 Earth Diameters (ED). The preliminary results for two galaxies, NGC 3079 and NGC 4258, at baselines longer than one ED indicate masering environments and excitation conditions in these galaxies that are distinctly different. Further observations of NGC 4258 at even longer baselines are expected to reveal more of the physics of individual emission regions.
MASERS: A Python package for statistical equilibrium calculations applied to masers
Authors: van Rooyen R. , van der Walt D. J.
Published: July 2018

The study of astrophysical maser formation provides a useful probe of the chemical composition and physical conditions of the sources they are observed in. This exploration requires continuously solving the SE equations for the populations of the energy levels in search of conditions that will produce an inversion. After evaluation of available implementations applying the Escape Probability approximation, the masers solver was developed to provide an efficient and robust matrix inversion calculation. This open source package is hosted at https://bitbucket.org/ruby_van_rooyen/masers.
Full polarization analysis of OH masers at 18-cm toward W49 A star forming region
Authors: Asanok K. , Kramer B. Hutawarakorn , Etoka S. , Gray M. , Richards A. M. S. , Gasiprong N. , Naochang N.
Published: July 2018

W49 A is a star-forming region (SFR) found in the constellation of Aquila. It contains 3 active regions: W49 North (W49 N), W49 South West (W49 SW) and W49 South (W49 S). We present preliminary results from two epochs (e-)MERLIN observations of all ground-state OH masers towards the star-forming region (SFR) complex W49 A. The first epoch of observations was done in full-polarization mode with MERLIN in 2005 while the second epoch was obtained only in dual circular polarization during the test observations of the upgraded e-MERLIN in 2013. The overall maser spatial distributions in both epochs are in good agreement. We found several new high velocity maser features up to +34 km s−1 and −28 km s−1. The magnetic field strengths are between 1.1 to 10.8 mG. All three sources show evidence of magnetic field reversal.
Dynamics of jet/outflow driven by high-mass young stellar object revealed by KaVA 22 GHz water maser observations
Authors: Kim Jungha , Hirota Tomoya , Kim Kee-Tae , Sugiyama Koichiro ,   KaVA Science Working Group for Star-formation
Published: July 2018

We have started survey observations of the 22 GHz water maser sources associated with high-mass young stellar objects (HM-YSOs) as a part of the KaVA (KVN and VERA Array) large program (LP). The aim of our LP is to understand dynamical evolution of jets/outflows from HM-YSOs by analyzing 3D velocity structures of water maser features. In the first year (2016-2017), an imaging survey toward 25 HM-YSOs has been conducted and the 22 GHz water masers are detected toward 21 sources. Spatial distributions of maser features for individual sources are mapped. To complement physical properties in the vicinity of HM-YSOs, we have carried out ALMA cycle 3 observations of thermal molecular lines and continuum emissions toward 11 selected samples. Summary of the KaVA first year observations and the initial results from the ALMA toward one of our targets, G25.82-0.17, are reported.
Maser science with the Square Kilometre Array
Authors: Bonaldi Anna
Published: July 2018

The Square Kilometre Array (SKA), reaching a collecting area of one square kilometre, will be the world’s largest radio telescope. Even in its first stage of deployment (SKA1, whose construction will be completed in 2026) it will enable transformational science on a very broad range of scientific objectives. Amongst them, there is the investigation of several Galactic and extra-galactic Masers. In this paper I will present the status of the SKA project and I will describe the capabilities of the SKA, with a focus on those that are more relevant for Maser science.
Periodic masers in massive star forming regions
Authors: Goedhart S. , van Rooyen R. , van der Walt D. J. , Maswanaganye J. P. , MacCleod G. C. , Sanna A.
Published: July 2018

The first periodic Class II methanol maser was reported on in 2003. Since that time, a number of different monitoring programmes have found periodic masers, as well as other modes of variability. In a few cases, periodicity has been found in other maser species such as formaldehyde and water. Several distinct characteristics of light curves have been noted, possibly pointing to different underlying mechanisms for periodicity if one assumes a linear response to incoming radiation. I will give a brief overview of the known periodic sources, discuss current theories, and present new results obtained from monitoring mainline hydroxyl masers using the seven-element Karoo Array Telescope (KAT-7) during its science verification phase.
The CepHeus-A Star formation and proper Motions (CHASM) Survey
Authors: Sanna Alberto
Published: July 2018

The “CepHeus-A Star formation and proper Motions” (CHASM) survey is a large project consisting of a combination of astrometric Very Long Baseline Array (VLBA) and Jansky Very Large Array (VLA) observations, to map both the stellar and dense molecular gas components in the star-forming region Cepheus A. With the VLBA, we make use of the CH3OH and H2O maser emission in the vicinity of Cepheus A HW2, in order to measure accurate proper motions and parallax distances to both T Tauri stars and massive young stellar objects (YSOs) belonging to the same star-forming region. With the Jansky VLA, we make use of the interstellar thermometer NH3, in order to image the molecular clump surrounding Cepheus A HW2 and to determine its physical conditions. By combining these informations all together, we can provide, for instance, a direct measurement of the Bondi-Hoyle accretion radius for a massive young star, namely, HW2.
Progress toward an accurate Hubble Constant
Authors: Suyu Sherry H.
Published: July 2018

The Hubble constant is a key cosmological parameter that sets the present-day expansion rate as well as the age, size, and critical density of the Universe. Intriguingly, there is currently a tension in the measurements of its value in the standard flat ΛCDM model – observations of the Cosmic Microwave Background with the Planck satellite lead to a value of the Hubble constant that is lower than the measurements from the local Cepheids-supernovae distance ladder and strong gravitational lensing. Precise and accurate Hubble constant measurements from independent probes, including water masers, are necessary to assess the significance of this tension and the possible need of new physics beyond the current standard cosmological model. We present the progress toward an accurate Hubble constant determination.
Conference Summary
Authors: Diamond Philip J.
Published: July 2018

IAU Symposium 336, Astrophysical Masers: Unlocking the Mysteries of the Universe, took place between 4 - 8 September, 2017 in Cagliari, on the beautiful island of Sardinia. The Symposium, the fifth focusing on masers as a tool for astrophysics, was dedicated to our friend and colleague Malcolm Walmsley, who sadly passed away shortly before the meeting. To quote Karl Menten: “Malcolm made numerous fundamental contributions to our understanding of the physics and chemistry of star formation and the interstellar medium. He was an exceptional scientist, a highly esteemed colleague and a true gentleman”. Vale Malcolm. The topics discussed at the symposium covered a huge range, from star-formation, evolved stars, galaxies and their constituents, super-massive black-holes to cosmology.
Chemical differentiation in the inner envelope of a young high-mass protostar associated with Class II methanol maser emission
Authors: Csengeri T. , Bontemps S. , Wyrowski F. , Belloche A. , Menten K. M. , Leurini S. ,   the SPARKS team
Published: July 2018

We present a case study of a single high-mass protostar associated with an infrared quiet massive clump selected from the ATLASGAL survey. The thermal dust emission reveals a single collapsing object associated with a prominent molecular outflow. We detect bright emission from a torsionally excited state transition of CH3OH offset from the protostar that is well explained by shocks at the transition from the infalling envelope onto an accretion disk.
Exploring the Nature of MMB sources: A Search for Class I Methanol Masers and their Outflows
Authors: Cunningham Nichol , Fuller Gary , Avison Adam , Breen Shari
Published: July 2018

We present the initial results from a class I 44-GHz methanol maser follow-up survey, observed with the MOPRA telescope, towards 272 sources from the Methanol Multi-beam survey (MMB). Over half (∼60%) of the 6.7 GHz class II MMB maser sources are associated with a class I 44-GHz methanol maser at a greater than 5σ detection level. We find that class II MMB masers sources with an associated class I methanol maser have stronger peak fluxes compared to regions without an associated class I maser. Furthermore, as part of the MOPRA follow-up observations we simultaneously observed SiO emission which is a known tracer of shocks and outflows in massive star forming regions. The presence of SiO emission, and potentially outflows, is found to be strongly associated with the detection of class I maser emission in these regions.
A new terrestrial millipede fauna of earliest Carboniferous (Tournaisian) age from southeastern Scotland helps fill ‘Romer's Gap'
Authors: Ross Andrew J. , Edgecombe Gregory D. , Clark Neil D. L. , Bennett Carys E. , Carrió Vicen , Contreras-Izquierdo Rubén , Crighton Bill
Published: July 2018

A diverse millipede (diplopod) fauna has been recovered from the earliest Carboniferous (Tournaisian) Ballagan Formation of the Scottish Borders, discovered by the late Stan Wood. The material is generally fragmentary; however, six different taxa are present based on seven specimens. Only one displays enough characters for formal description and is namedWoodesmus sheariRoss, Edgecombe & Clark gen. & sp. nov. The absence of paranota justifies the erection of Woodesmidae fam. nov. within the Archipolypoda. The diverse fauna supports the theory that an apparent lack of terrestrial animal fossils from ‘Romer's Gap' was due to a lack of collecting and suitable deposits, rather than to low oxygen levels as previously suggested.
Sex hormones and venous thromboembolism – from contraception to hormone replacement therapy
Authors: Beyer-Westendorf Jan , Bauersachs Rupert , Hach-Wunderle Viola , Zotz Rainer B. , Rott Hannelore
Published: July 2018

Abstract. The use of sex hormones such as combined oral contraceptives (COC) or hormone replacement therapy (HRT) increases the risk for venous thromboembolism (VTE) considerably, especially in patients with an increased intrinsic risk for thromboembolic complications. Despite public and media attention and increasing scientific evidence, prescription patterns seem to be hard to change. It is well recognized that the patient’s baseline risk is the most relevant factor in the absolute risk for developing VTE. The relative risk increase associated with sex hormones, depends on the type and dosage of hormones, the route of application (oral, vaginal, transdermal), and for COC, on the specific combination of oestrogen and gestagen components. Consequently, a careful decision for or against any specific type of hormone treatment needs to be based on an assessment of the patient’s risk profile (disposition) as well as on the treatment-associated risks and benefits (exposition). This review discusses the most common sex hormone treatments in contraception and HRT, the relevance for VTE risk patients, and strategies to counsel patients with regard to hormone use according to their risk profiles.

Keywords: Oral contraceptives, hormonal contraception, hormone replacement therapy, venous thromboembolism
Microseismic Emissions During Pneumatic Fracturing: A Numerical Model to Explain the Experiments
Authors: Turquet Antoine L. , Toussaint Renaud , Eriksen Fredrik Kvalheim , Daniel Guillaume , Koehn Daniel , Flekkøy Eirik G.
Published: July 2018

Modeling of fluid injection processes into a deformable porous medium is a challenging area of physics that has a wide range of applications like the food, construction, and petroleum industries. In this research, we investigate pneumatic fracturing of a porous medium experimentally and numerically in a Hele‐Shaw cell. In the experiments, we inject air into the porous medium (initially random loose packed) to create compaction, channeling, and fracturing while monitoring the cell with accelerometers and a high‐speed camera. Furthermore, we develop a numerical model in two steps: (1) a poroelastoplasticity‐based model to explain dynamic fluid pressure variations and (2) a solid stress model based on Janssen's theory. The contributions of the different pressure sources air in channels and solid stress in the experiments, and the simulations are compared with respect to amplitude and frequency. Afterward, the variations of the normal stress exerting on the plates are convolved with a Lamb Wave green function to generate acoustic emissions numerically. The physics behind the evolution of the experimentally recorded power spectrum of the out‐of‐plane plate vibrations are explained using numerical models. The frequency bands (in the simulated power spectra) are influenced by the size of the opened channels and the Hele‐Shaw cell and are in the same range with the experimentally measured peaks of the acoustic emissions.
The Impact of Realistic Elastic Properties on Inversions of Shallow Subduction Interface Slow Slip Events Using Seafloor Geodetic Data
Authors: Williams Charles A. , Wallace Laura M.
Published: July 2018

We examine the effects of topography and material heterogeneity on geodetic inversions of shallow slow slip at the Hikurangi Subduction Margin, New Zealand. Offshore vertical data from absolute pressure gauges constrain our results. Using a finite element code to generate our Green's functions, we find that topography has a relatively small effect, reducing the seismic potency by only about 5% when compared to a flat model. When material heterogeneity from a New Zealand‐wide seismic velocity model is taken into account, we find an extremely large effect, with the seismic potency increasing by 58% or more. In previous work, we found the opposite effect for deeper slip events, where models including elastic property variations result in ~20% more slip than when they are neglected. Our previous results for deeper events are consistent with a simplified model that considers the elastic property contrasts between a strong subducting slab and a weaker overriding plate. To understand the opposite behavior of our shallower models, we use synthetic forward models and view material property gradients in terms of additional body forces. We find that gradients in elastic properties can produce very different surface displacements near the source than simple contrasts, thus explaining the contrasting results for shallow slip events. Combined with our previous results for deeper events, this implies that neglecting material heterogeneity in slow slip inversions may result in overestimates in the amount of slip for deeper events and underestimates for shallow events.
Capturing the Mesoarchean Emergence of Continental Crust in the Coorg Block, Southern India
Authors: Roberts Nick M. W. , Santosh M.
Published: July 2018

The emergence of Earth's continental crust above sea level is debated. To assess whether emergence can be observed at a regional scale, we present zircon U‐Pb‐Hf‐O isotope data from magmatic rocks of the Coorg Block, southern India. A 3.5‐Ga granodiorite records the earliest felsic crust in the region. Younger phases of magmatism at 3.37–3.27 and 3.19–3.14 Ga, comprising both reworked crust and juvenile material, record successive crustal maturation. We interpret an elevation in δ18O through time as an increase in both the amount of sediment recycling and hence, crustal thickening, as well as an increase in the emerged area of continental crust available for weathering. Geochemical signatures do not point to any apparent change in geodynamic regime. We interpret the isotopic evolution of these rocks as solely reflecting regional emergence and thickening of the continental crust, assisted by the increasing strength of the lithosphere.
South Atlantic Forced Multidecadal Teleconnection to the Midlatitude South Indian Ocean
Authors: Xue Jiaqing , Sun Cheng , Li Jianping , Mao Jiangyu
Published: July 2018

Sea surface temperature (SST) in the midlatitude south Indian Ocean (MSIO) exhibits prominent multidecadal fluctuations that have profound climate impacts for regions around the Indian Ocean. Observational analysis suggests that these multidecadal fluctuations can be explained by remote forcing from South Atlantic multidecadal variability. A suite of Atlantic Pacemaker experiments performs well in reproducing the observed MSIO SST multidecadal variation and its association with the South Atlantic. This transbasin covariability can be described by an atmospheric bridge mechanism, in which South Atlantic multidecadal variability‐related SST warming weakens regional meridional circulation over the South Atlantic, suppressing convection over tropical Africa. The reduced diabatic heating then drives a cold atmospheric Kelvin wave that penetrates into the tropical Indian Ocean, leading to an anomalous cyclonic circulation there that weakens the westerlies over the MSIO and subsequently triggers the warming of MSIO. This initial warming is further amplified by local SST‐water vapor positive feedback over the MSIO.
Sulfur Degassing From Steam‐Heated Crater Lakes: El Chichón (Chiapas, Mexico) and Víti (Iceland)
Authors: Hasselle N. , Rouwet D. , Aiuppa A. , Jácome‐Paz M. P. , Pfeffer M. , Taran Y. , Campion R. , Bitetto M. , Giudice G. , Bergsson B.
Published: July 2018

The composition of the gases released by El Chichón (Chiapas, Mexico) and Víti (Askja volcano, Iceland) volcanic lakes is examined by Multi‐GAS for the first time. Our results demonstrate that H2S and SO2 are degassed by these pH 2–3 lakes. We find higher CO2/H2S and H2/H2S ratios in the lakes' emissions (31–5,685 and 0.6–35, respectively) than in the fumarolic gases feeding the lakes (13–33 and 0.08–0.5, respectively), evidencing that only a fraction (0.2–5.4% at El Chichón) of the H2S(g) contributed by the subaquatic fumaroles ultimately reaches the atmosphere. At El Chichón, we estimate a H2S output from the crater lake of 0.02–0.06 t/day. Curiously, SO2 is also detected at trace levels in the gases released from both lakes (0.003–0.3 ppmv). We propose that H2S supplied into the lakes initiates a series of complex oxidation reactions, having sulfite as an intermediate product, and ultimately leading to SO2 production and degassing.
Nitrogen Solubility in Core Materials
Authors: Speelmanns Iris M. , Schmidt Max W. , Liebske Christian
Published: July 2018

During accretion, nitrogen was distributed between metal melt, silicate melt, and the atmosphere and today's N deficit of bulk silicate Earth with respect to chondrites may be due to segregation into the core and/or atmospheric losses. To examine the former, we experimentally determined N solubilities in Fe‐dominated metal melts at 1200–1800 °C, 0.4–9.0 GPa. Results show that pressure has a strong positive influence on N solubility, increasing from 1.0 to 7.4 wt% at 1–9 GPa (1400 °C) while temperature has the inverse effect, N solubility decreasing from 1.3 to 0.6 wt% at 1200–1800 °C (1 GPa). The solubility data are parameterized as function of pressure and temperature. Our results suggest that core‐forming metal melts can dissolve large quantities of N, and the potential N contribution to the Earth's core density deficit could hence be much larger than previously assumed. Most importantly, N in the deep reduced mantle should be stored in the small metal fractions and not in silicates.
Matched Field Processing of Three‐Component Seismic Array Data Applied to Rayleigh and Love Microseisms
Authors: Gal M. , Reading A. M. , Rawlinson N. , Schulte‐Pelkum V.
Published: July 2018

We extend three‐component plane wave beamforming to a more general form and devise a framework, which incorporates velocity heterogeneities of the seismic propagation medium and allows us to estimate accurately sources that do not follow the simple plane wave assumption. This is achieved by utilizing fast marching to track seismic wave fronts for given surface wave phase velocity maps. The resulting matched field processing approach is used to study the surface wave locations of Rayleigh and Love waves at 8 and 16 s based on data from four seismic arrays in the western United States. By accurately accounting for the path propagation effects, we are able to map microseism surface wave source locations more accurately than conventional plane wave beamforming. In the primary microseisms frequency range, Love waves are dominant over Rayleigh waves and display a directional radiation pattern. In the secondary microseisms range, we find the general source regions for both wave types to be similar, but on smaller scales differences are observed. Love waves are found to originate from a larger area than Rayleigh waves and their energy is equal or slightly weaker than Rayleigh waves. The energy ratios are additionally found to be source location dependent. Potential excitation mechanisms are discussed which favor scattering from Rayleigh‐to‐Love waves.
Correction Alternative mechanisms of miR-34a regulation in cancer
Authors: Slabáková Eva , Culig Zoran , Remšík Ján , Souček Karel
Published: July 2018

The PDF and HTML versions of the article have been updated to include the Creative Commons Attribution 4.0 International License information.
A coastal coccolithophore maintains pH homeostasis and switches carbon sources in response to ocean acidification
Authors: Liu Yi-Wei , Eagle Robert A. , Aciego Sarah M. , Gilmore Rosaleen E. , Ries Justin B.
Published: July 2018

Ocean acidification will potentially inhibit calcification by marine organisms; however, the response of the most prolific ocean calcifiers, coccolithophores, to this perturbation remains under characterized. Here we report novel chemical constraints on the response of the widespread coccolithophore speciesOchrosphaera neapolitana(O. neapolitana) to changing-CO2conditions. We cultured this algae under threepCO2-controlled seawater pH conditions (8.05, 8.22, and 8.33). Boron isotopes within the algae’s extracellular calcite plates show that this species maintains a constant pH at the calcification site, regardless of CO2-induced changes in pH of the surrounding seawater. Carbon and oxygen isotopes in the algae’s calcite plates and carbon isotopes in the algae’s organic matter suggest thatO. neapolitanautilize carbon from a single internal dissolved inorganic carbon (DIC) pool for both calcification and photosynthesis, and that a greater proportion of dissolved CO2relative to HCO3−enters the internal DIC pool under acidified conditions. These two observations may explain howO. neapolitanacontinues calcifying and photosynthesizing at a constant rate under different atmospheric-pCO2conditions.
Concerted pulsatile and graded neural dynamics enables efficient chemotaxis in C. elegans
Authors: Itskovits Eyal , Ruach Rotem , Kazakov Alexander , Zaslaver Alon
Published: July 2018

The ability of animals to effectively locate and navigate toward food sources is central for survival. Here, using C. elegans nematodes, we reveal the neural mechanism underlying efficient navigation in chemical gradients. This mechanism relies on the activity of two types of chemosensory neurons: one (AWA) coding gradients via stochastic pulsatile dynamics, and the second (AWCON) coding the gradients deterministically in a graded manner. The pulsatile dynamics of the AWA neuron adapts to the magnitude of the gradient derivative, allowing animals to take trajectories better oriented toward the target. The robust response of AWCON to negative derivatives promotes immediate turns, thus alleviating the costs incurred by erroneous turns dictated by the AWA neuron. This mechanism empowers an efficient navigation strategy that outperforms the classical biased-random walk strategy. This general mechanism thus may be applicable to other sensory modalities for efficient gradient-based navigation.
Drug capture materials based on genomic DNA-functionalized magnetic nanoparticles
Authors: Blumenfeld Carl M. , Schulz Michael D. , Aboian Mariam S. , Wilson Mark W. , Moore Terilynn , Hetts Steven W. , Grubbs Robert H.
Published: July 2018

Chemotherapy agents are notorious for producing severe side-effects. One approach to mitigating this off-target damage is to deliver the chemotherapy directly to a tumor via transarterial infusion, or similar procedures, and then sequestering any chemotherapeutic in the veins draining the target organ before it enters the systemic circulation. Materials capable of such drug capture are yet to be fully realized. Here, we report the covalent attachment of genomic DNA to iron-oxide nanoparticles. With these magnetic materials, we captured three common chemotherapy agents—doxorubicin, cisplatin, and epirubicin—from biological solutions. We achieved 98% capture of doxorubicin from human serum in 10 min. We further demonstrate that DNA-coated particles can rescue cultured cardiac myoblasts from lethal levels of doxorubicin. Finally, the in vivo efficacy of these materials was demonstrated in a porcine model. The efficacy of these materials demonstrates the viability of genomic DNA-coated materials as substrates for drug capture applications.
Publisher Correction: FGF signalling controls the specification of hair placode-derived SOX9 positive progenitors to Merkel cells
Authors: Nguyen Minh Binh , Cohen Idan , Kumar Vinod , Xu Zijian , Bar Carmit , Dauber-Decker Katherine L. , Tsai Pai-Chi , Marangoni Pauline , Klein Ophir D. , Hsu Ya-Chieh , Chen Ting , Mikkola Marja L. , Ezhkova Elena
Published: July 2018

The originally published version of this Article contained an error in Figure 2. In panel e, the blue bar was incorrectly labelled ‘KRT8(+)/TOMATO(-)’. Furthermore, during the process of preparing a correction, the publication date of the Article was inadvertently changed to June 20th 2018. Both of these errors have been corrected in the PDF and HTML versions of the Article.
Acceleration profiles and processing methods for parabolic flight
Authors: Carr Christopher E. , Bryan Noelle C. , Saboda Kendall N. , Bhattaru Srinivasa A. , Ruvkun Gary , Zuber Maria T.
Published: July 2018

Parabolic flights provide cost-effective, time-limited access to “weightless” or reduced gravity conditions, facilitating research and validation activities that complement infrequent and costly access to space. Although parabolic flights have been conducted for decades, reference acceleration profiles and processing methods are not widely available. Here we present a solution for collecting, analyzing, and classifying the altered gravity environments experienced during parabolic flights, which we validated during a Boeing 727-200F flight with 20 parabolas. All data and analysis code are freely available. Our solution can be integrated with diverse experimental designs, does not depend upon accelerometer orientation, and allows unsupervised classification of all phases of flight, providing a consistent and open-source approach to quantifying gravito-inertial accelerations (GIA), or g levels. As academic, governmental, and commercial use of space advances, data availability and validated processing methods will enable better planning, execution, and analysis of parabolic flight experiments, and thus facilitate future space activities.
Gene expression related to trehalose metabolism and its effect on Volvariella volvacea under low temperature stress
Authors: Zhao Xu , Song Xiaoxia , Li Yapeng , Yu Changxia , Zhao Yan , Gong Ming , Shen Xuexiang , Chen Mingjie
Published: July 2018

The mechanism of the low temperature autolysis of Volvariella volvacea (V. volvacea) has not been thoroughly explained, and trehalose is one of the most important osmolytes in the resistance of fungi to adversity. The present study used the low temperature sensitive V. volvacea strain V23 and the low temperature tolerant strain VH3 as test materials. Intracellular trehalose contents under low temperature stress in the two strains were measured by high performance liquid chromatography (HPLC). Quantitative real-time PCR (qPCR) analysis was carried out to study the transcriptional expression differences of enzymes related to trehalose metabolism. And trehalose solution was exogenously added during the cultivation of fruit bodies of V. volvacea. The effect of exogenous trehalose solution on the anti-hypothermia of fruit bodies was studied by evaluating the sensory changes under low temperature storage after harvest. The results showed that the intracellular trehalose content in VH3 was higher than that in V23 under low temperature stress. In the first 2 h of low temperature stress, the expression of trehalose-6-phosphate phosphatase (TPP) gene involved in trehalose synthesis decreased, while the expression of trehalose phosphorylase (TP) gene increased. The expression of TPP gene was almost unchanged in VH3, but it decreased dramatically in V23 at 4 h of low temperature stress. The expression levels of TPP and TP genes in VH3 was significantly higher than that in V23 from 6 h to 8 h of low temperature stress. TP gene may be a crucial gene of trehalose metabolism, which was more inclined to synthesize trehalose during low temperature stress. In addition, the sensory traits of V. volvacea fruit bodies stored at 4 °C were significantly improved by the application of exogenous trehalose compared with the controls. Thus, trehalose could help V. volvacea in response to low temperature stress and high content of it may be one of the reasons that why VH3 strain was more tolerant to the low temperature stress than V23 strain.
Normative data of contact heat evoked potentials from the lower extremities
Authors: Rosner J. , Hostettler P. , Scheuren P. S. , Sirucek L. , Rinert J. , Curt A. , Kramer J. L. K. , Jutzeler C. R. , Hubli M.
Published: July 2018

Contact heat evoked potentials (CHEPs) have become an acknowledged research tool in the assessment of the integrity of the nociceptive system and gained importance in the diagnostic work-up of patients with suspected small fiber neuropathy. For the latter, normative values for CHEP amplitude and latency are indispensable for a clinically meaningful interpretation of the results gathered in patients. To this end, CHEPs were recorded in 100 healthy subjects over a wide age range (20–80 years) and from three different dermatomes of the lower extremities (L2, L5, and S2). A normal baseline (35–52 °C) and increased baseline stimulation (42–52 °C) were applied. Statistical analysis revealed significant effects of stimulation site, stimulation intensity, and sex on CHEP parameters (N2 latency, N2P2 amplitude, and NRS). Significant positive correlations of body height with N2 latency, and pain ratings with N2P2 amplitudes were observed. This is the first time that normative values have been obtained from multiple dermatomes of the lower extremities. The present dataset will facilitate the clinical application of CHEPs in the neurophysiological diagnosis of small fiber neuropathy and by discerning pathological findings help establish a proximal-distal gradient of nerve degeneration in polyneuropathies.
Experimentally induced metamorphosis in highly regenerative axolotl (ambystoma mexicanum) under constant diet restructures microbiota
Authors: Demircan Turan , Ovezmyradov Guvanch , Yıldırım Berna , Keskin İlknur , İlhan Ayşe Elif , Fesçioğlu Ece Cana , Öztürk Gürkan , Yıldırım Süleyman
Published: July 2018

Axolotl (Ambystoma mexicanum) is a critically endangered salamander species and a model organism for regenerative and developmental biology. Despite life-long neoteny in nature and in captive-bred colonies, metamorphosis of these animals can be experimentally induced by administering Thyroid hormones (THs). However, microbiological consequences of this experimental procedure, such as host microbiota response, remain largely unknown. Here, we systematically compared host bacterial microbiota associated with skin, stomach, gut tissues and fecal samples, between neotenic and metamorphic axolotls based on 16S rRNA gene sequences. Our results show that distinct bacterial communities inhabit individual organs of axolotl and undergo substantial restructuring through metamorphosis. Skin microbiota among others, shifted sharply, as highlighted by a major transition from Firmicutes-enriched to Proteobacteria-enriched relative abundance and precipitously decreased diversity. Fecal microbiota of neotenic and metamorphic axolotl shared relatively higher similarity, suggesting that diet continues to shape microbiota despite fundamental transformations in the host digestive organs. We also reproduced the previous finding on reduction in regenerative capacity in limbs of axolotl following metamorphosis, highlighting the need to investigate whether shifts in microbiota is causally linked to regenerative capacity of axolotl. The initial results on axolotl microbiota provide novel insights into microbiological aspects of axolotl metamorphosis and will establish a baseline for future in-depth studies.
Food Chemicals Disrupt Human Gut Microbiota Activity And Impact Intestinal Homeostasis As Revealed By In Vitro Systems
Authors: Defois Clémence , Ratel Jérémy , Garrait Ghislain , Denis Sylvain , Le Goff Olivier , Talvas Jérémie , Mosoni Pascale , Engel Erwan , Peyret Pierre
Published: July 2018

Growing evidence indicates that the human gut microbiota interacts with xenobiotics, including persistent organic pollutants and foodborne chemicals. The toxicological relevance of the gut microbiota-pollutant interplay is of great concern since chemicals may disrupt gut microbiota functions, with a potential impairment of host homeostasis. Herein we report within batch fermentation systems the impact of food contaminants (polycyclic aromatic hydrocarbons, polychlorobiphenyls, brominated flame retardants, dioxins, pesticides and heterocyclic amines) on the human gut microbiota by metatranscriptome and volatolome i.e. “volatile organic compounds” analyses. Inflammatory host cell response caused by microbial metabolites following the pollutants-gut microbiota interaction, was evaluated on intestinal epithelial TC7 cells. Changes in the volatolome pattern analyzed via solid-phase microextraction coupled to gas chromatography-mass spectrometry mainly resulted in an imbalance in sulfur, phenolic and ester compounds. An increase in microbial gene expression related to lipid metabolism processes as well as the plasma membrane, periplasmic space, protein kinase activity and receptor activity was observed following dioxin, brominated flame retardant and heterocyclic amine exposure. Conversely, all food contaminants tested induced a decreased in microbial transcript levels related to ribosome, translation and nucleic acid binding. Finally, we demonstrated that gut microbiota metabolites resulting from pollutant disturbances may promote the establishment of a pro-inflammatory state in the gut, as stated with the release of cytokine IL-8 by intestinal epithelial cells.
The case for rejecting the memristor as a fundamental circuit element
Authors: Abraham Isaac
Published: July 2018

The memory resistor with the moniker memristor was a harmless postulate in 1971. Since 2008 a device that claims to be the memristor is on the prowl, seeking recognition as a fundamental circuit element, sometimes wanting electronics textbooks to be rewritten, always promising remarkable digital, analog and neuromorphic computing possibilities. A systematic discussion about the fundamental nature of the device is almost absent within the memristor community. Advocates use incomplete constitutive relationships, ignore concepts of activity/passivity and aver that nonlinearity is central to their case. Few researchers have examined these claims. Our report investigates the assertion that the memristor is a fundamental passive circuit element, from the fresh perspective that electrical engineering is the science of charge management. We demonstrate with a periodic table of fundamental elements that the 2008 memristor is not the 1971 postulate and neither of them is fundamental. The ideal memristor is an unphysical active device and any physically realizable memristor is a nonlinear composition of resistors with active hysteresis. We also show that there exists only three fundamental passive circuit elements.
A blockade of PI3Kγ signaling effectively mitigates angiotensin II-induced renal injury and fibrosis in a mouse model
Authors: Yu Xinyi , Xia Yunfeng , Zeng Liyi , Zhang Xi , Chen Liqun , Yan Shujuan , Zhang Ruyi , Zhao Chen , Zeng Zongyue , Shu Yi , Huang Shifeng , Lei Jiayan , Yuan Chengfu , Zhang Linghuan , Feng Yixiao , Liu Wei , Huang Bo , Zhang Bo , Luo Wenping , Wang Xi , Zhang Hongmei , Haydon Rex C. , Luu Hue H. , He Tong-Chuan , Gan Hua
Published: July 2018

Chronic kidney disease (CKD) poses a formidable challenge for public healthcare worldwide as vast majority of patients with CKD are also at risk of accelerated cardiovascular disease and death. Renal fibrosis is the common manifestation of CKD that usually leads to end-stage renal disease although the molecular events leading to chronic renal fibrosis and eventually chronic renal failure remain to be fully understood. Nonetheless, emerging evidence suggests that an aberrant activation of PI3Kγ signaling may play an important role in regulating profibrotic phenotypes. Here, we investigate whether a blockade of PI3Kγ signaling exerts any beneficial effect on alleviating kidney injury and renal fibrosis. Using a mouse model of angiotensin II (Ang II)-induced renal damage, we demonstrate that PI3Kγ inhibitor AS605240 effectively mitigates Ang II-induced increases in serum creatinine and blood urea nitrogen, renal interstitial collagen deposition, the accumulation of ECM proteins and the expression of α-Sma and fibrosis-related genes in vivo. Mechanistically, we reveal that AS605240 effectively inhibits Ang II-induced cell proliferation and phosphorylation of Akt in fibroblast cells. Furthermore, we demonstrate that Ang II-upregulated expression of IL-6, Tnf-α, IL-1β and Tgf-β1 is significantly attenuated in the mice treated with AS605240. Taken together, our results demonstrate that PI3Kγ may function as a critical mediator of Ang II-induced renal injury and fibrosis. It is thus conceivable that targeted inhibition of PI3Kγ signaling may constitute a novel therapeutic approach to the clinical management of renal fibrosis, renal hypertension and/or CKD.
An approach to predict the height of fractured water-conducting zone of coal roof strata using random forest regression
Authors: Zhao Dekang , Wu Qiang
Published: July 2018

Water inrushes from coal-roof strata account for a great proportion of coal mine accidents, and the height of fractured water-conducting zone (FWCZ) is of significant importance for the safe production of coal mines. A novel and promising model for predicting the height of FWCZ was proposed based on random forest regression (RFR), which is a powerful intelligent machine learning algorithm. RFR has high prediction accuracy and is robust in dealing with the complicated and non-linear problems. Also, it can evaluate the importance of the variables. In this study, the proposed model was applied to Hongliu Coal Mine in Northwest China. 85 field measured samples were collected in total, with 60 samples (70%) used for training and 20 (30%) used for validation. For comparison, a support vector machine (SVM) model was also constructed for the prediction. The results show that the two models are in accordance with the field measured data, and RFR shows a better performance on good tolerance to outliers and noises and efficiently on high-dimensional data sets. It is demonstrated that RFR is more practicable and accurate to predict the height of FWCZ. The achievements will be helpful in preventing and controlling the water inrushes from coal-roof strata, and also can be extended to various engineering applications.
Electronic excitations stabilized by a degenerate electron gas in semiconductors
Authors: Nenstiel C. , Callsen G. , Nippert F. , Kure T. , Schlichting S. , Jankowski N. , Hoffmann M. P. , Dadgar A. , Fritze S. , Krost A. , Wagner M. R. , Hoffmann A. , Bechstedt F.
Published: July 2018

Excitons in semiconductors and insulators consist of fermionic subsystems, electrons and holes, whose attractive interaction facilitates bound quasiparticles with quasi-bosonic character. In the presence of a degenerate electron gas, such excitons dissociate due to free carrier screening. Despite their absence, we found pronounced emission traces in the below-band-edge region of bulk, germanium-doped GaN up to a temperature of 100 K, mimicking sharp spectral features at high free electron concentrations (3.4E19–8.9E19 cm−3). Our interpretation of the data suggests that a degenerate, three-dimensional electron gas stabilizes a novel class of quasiparticles, which we name collexons. These many-particle complexes are formed by exchange of electrons with the Fermi gas. The potential observation of collexons and their stabilization with rising doping concentration is enabled by high crystal quality due to the almost ideal substitution of host atoms with dopants.
Surface dependent enhancement in water vapor permeation through nanochannels
Authors: Rangharajan Kaushik K. , Mohana Sundaram Prashanth , Conlisk A. T. , Prakash Shaurya
Published: July 2018

Transmission resistance for selective water vapor permeation through hydrophobic conduits with a varying degree of surface wettability is estimated inside a nanofluidic device.
A zeolite-like MOF based on a heterotritopic linker of imidazolyl, carboxyl and pyridine with a long-sought uks net on Schwarz's D-surface
Authors: Ye Chun-Rong , Zheng Ji , Li Mian , Huang Xiao-Chun
Published: July 2018

The title complex is the first zeolite-like MOF reported to have a long-sought uks net.
The perfluorinated alcohols c-C6F11OH, c-C6F10-1,1-(OH)2 and c-C6F10-1-(CF3)OH
Authors: Schaab Jonas , Schwab Miriam , Kratzert Daniel , Schwabedissen Jan , Stammler Hans-Georg , Mitzel Norbert W. , Krossing Ingo
Published: July 2018

The thermally unstable α-fluoroalcohol undecafluorocyclohexanol (c-C6F11OH) was prepared by addition of hydrogen fluoride to the corresponding ketone.
Group 13 element containing conformationally rigid “N–E–N” heteroatomic bridged [3.3](2,6)pyridinophanes (E = B, Al)
Authors: Bawari Deependra , Negi Chandrakala , Jaiswal Kuldeep , Prashanth Billa , Choudhury Angshuman Roy , Singh Sanjay
Published: July 2018

Donor–acceptor interactions (Npy⋯E) have been utilized to assemble conformationally rigid [3.3](2,6)pyridinophanes containing group 13 elements.
Crystal growth and piezoelectric characterization of mechanically stable ZnO nanostructure arrays
Authors: Lim T. , Ico G. , Jung K. , Bozhilov K. N. , Nam J. , Martinez-Morales A. A.
Published: July 2018

The highest piezoelectric performance of ZnO can be achieved by utilizing the piezoelectric operation along the c-axis due to its anisotropic permanent dipole moment.
Area negative thermal expansion in a mixed metal mixed organic MOF: “elevator-platform” mechanism induced by O–H⋯O hydrogen bonding
Authors: Shrivastava Ashutosh , Negi Lalita , Das Dinabandhu
Published: July 2018

Rare area negative thermal expansion of a new mixed metal mixed organic MOF has been described using an “elevator-platform” analogy induced by O–H⋯O hydrogen bonding.
Probing the structure–property–composition relationship in organic–inorganic tri-halide perovskites
Authors: Payne Julia L. , Ni Chengsheng , Harwell Jonathon R. , Jagadamma Lethy Krishnan , McDonald Calum , Mariotti Davide , Samuel Ifor D. W. , Irvine John T. S.
Published: July 2018

Here, we have synthesised a range of samples, with the formula (CH3NH3)1−2x(H3NC2H4NH3)xPbI3, with different levels of ethylenediammonium substitution to probe non-stoichiometry at the A-site of the perovskite.
Adsorption of charged macromolecules upon multicomponent responsive surfaces
Authors: Nunes Sandra C.C. , Cova Tânia F. G. G. , Dias Rita S. , Pais Alberto A. C. C.
Published: July 2018

A predictive model for polyelectrolyte adsorption upon responsive surfaces is presented, decoupling the effect of surface charges and crowders.
Small and large-scale distribution of four classes of antibiotics in sediment: association with metals and antibiotic resistance genes
Authors: Kerrigan Jill F. , Sandberg Kyle D. , Engstrom Daniel R. , LaPara Timothy M. , Arnold William A.
Published: July 2018

Associations between antibiotics (or metals) levels with antibiotic resistance gene abundance were lost as distance from anthropogenic inputs increased.
Retracted Article: Plasma-grafted amidoxime/metal–organic framework composites for the selective sequestration of U(vi)
Authors: Li Fengbo , Li Xiaoyu , Cui Pu , Sun Yubing
Published: July 2018

The selective sequestration mechanism of U(vi) by metal–organic framework supported amidoxime (AO/MOF) composites has been demonstrated by batch, XPS and EXAFS analyses.
A neuromorphic systems approach to in-memory computing with non-ideal memristive devices: from mitigation to exploitation
Authors: Payvand Melika , Nair Manu V. , Müller Lorenz K. , Indiveri Giacomo
Published: July 2018

In this paper, we present a spiking neural network architecture that supports the use of non-ideal memristive devices as synaptic elements and propose mixed-signal analog-digital interfacing circuits to mitigate/exploit such non-idealities for neuromorphic computation.
Acoustic formation of multicellular tumor spheroids enabling on-chip functional and structural imaging
Authors: Olofsson K. , Carannante V. , Ohlin M. , Frisk T. , Kushiro K. , Takai M. , Lundqvist A. , Önfelt B. , Wiklund M.
Published: July 2018

Combining a protein repellent coating and ultrasonic standing waves in microwells enables on-chip formation and confocal microscopy of multicellular tumor spheroids.
Nature-inspired entwined coiled carbon mechanical metamaterials: molecular dynamics simulations
Authors: Wu Jianyang , Shi Qiao , Zhang Zhisen , Wu Hong-Hui , Wang Chao , Ning Fulong , Xiao Senbo , He Jianying , Zhang Zhiliang
Published: July 2018

Elegant metastructures by which sparse carbon nanohelixes are entwined each other confer pronounced increase in stiffnesses to the native systems, beyond the scalability of mechanical springs in-parallel.
Highly robust and flexible n-type thermoelectric film based on Ag2Te nanoshuttle/polyvinylidene fluoride hybrids
Authors: Zhou Chongjian , Dun Chaochao , Ge Bangzhi , Wang Ke , Shi Zhongqi , Liu Guiwu , Carroll David L. , Qiao Guanjun
Published: July 2018

Illustration of the composition of an Ag2Te nanoshuttle/polyvinylidene fluoride hybrid film and demonstration of its highly robust and flexible performance.