bluuebunny/crossref_metadata_2025_split huggingface dataset:
Satellite Observations of Enhanced Chlorophyll Variability in the Southern California Bight
Authors: Kilpatrick Thomas , Xie Shang‐Ping , Miller Arthur J. , Schneider Niklas 
Published: September 2018

AbstractSatellite observations from the Moderate Resolution Imaging Spectroradiometer and Sea‐viewing Wide Field‐of‐view Sensor reveal a “tongue” of elevated near‐surface chlorophyll that extends into the Southern California Bight from Point Conception. A local chlorophyll maximum at the western edge of the bight, near the Santa Rosa Ridge, indicates that the chlorophyll is not solely due to advection from Point Conception but is enhanced by local upwelling. Chlorophyll in the bight peaks in May and June, in phase with the seasonal cycle of wind stress curl. The spatial structure and seasonal variability suggest that the local chlorophyll maximum is due to a combination of bathymetric influence from the Santa Rosa Ridge and orographic influence from the coastline bend at Point Conception, which causes sharp wind stress curl in the bight. High‐resolution glider observations show thermocline doming in May–June, in support of the local upwelling effect. Despite the evidence for local wind stress curl‐forced upwelling in the bight, we cannot rule out alternative mechanisms for the local chlorophyll maximum, such as iron supply from the ridge. Covariability between chlorophyll, surface wind stress, and sea surface temperature (SST) indicates that nonseasonal chlorophyll variability in the bight is closely related to SST, but the spatial patterns of SST influence vary by time scale: Subannual chlorophyll variability is linked to local wind‐forced upwelling, while interannual chlorophyll variability is linked to large‐scale SST variations over the northeast Pacific. This suggests a greater role for nonlocal processes in the bight's low‐frequency chlorophyll variability.
Moisture Distributions in Tropical Cold Pools From Equatorial Indian Ocean Observations and Cloud‐Resolving Simulations
Authors: Chandra Arunchandra S. , Zuidema Paquita , Krueger Steven , Kochanski Adam , de Szoeke Simon P. , Zhang Jianhao 
Published: September 2018

AbstractThe near‐surface characteristics of approximately 300 convective cold pools over the equatorial Indian Ocean are studied using surface meteorological variables from two equatorial Indian Ocean sites, radar imagery, and constrained cloud‐resolving simulations. The observed temperature drop at cold pool onset is typically accompanied by a drying and a decrease in moist static energy, signifying air transport from above the boundary layer through precipitation‐induced downdrafts. The decrease in the surface water vapor mixing ratio is more pronounced for stronger temperature drops. Composites reveal a slight enhancement in moisture coincident with a slight enhancement in temperature prior to the cold pool frontal temperature drop. The slight enhancements occur prior to a gust of increased surface winds, suggesting that the immediate cause is wind convergence. A statistical analysis combined with a focus on selected case studies is consistent with a view that the strongest cold pools occur in intermediate column water vapor paths with drier midtropospheres. Such conditions are more likely to occur during convectively suppressed phases of the Madden‐Julian Oscillation, when cold pool mesoscale organization facilitates the ability of cumulus congestus to reach the middle troposphere. Cold pools thus help explain why tropical cumulus congestus are common. Cloud‐resolving simulations capture realistic rain rates and surface wind changes (and thereby surface fluxes). The evolution in the model near‐surface moisture field is unrealistic, however, with an erroneous moisture enhancement inside the cold pool edge that is attributed to rain evaporation. This supports a further focus on the model representation of cold pool frontal dynamics and mixing.
Thermomechanical Stresses Drive Damage of Alpine Valley Rock Walls During Repeat Glacial Cycles
Authors: Grämiger Lorenz M. , Moore Jeffrey R. , Gischig Valentin S. , Loew Simon 
Published: September 2018

AbstractCycles of glaciation alter the temperature field in proximal alpine valley flanks, driving rock slope damage through thermomechanical stresses. Here we extend simplified assumptions of glacial debuttressing to quantitatively examine how paraglacial bedrock temperature changes, acting in concert with changing ice loads during Late Pleistocene and Holocene glacial cycles, create damage in adjacent rock slopes and prepare future slope instabilities. When in contact with temperate glacier ice, valley walls maintain near isothermal ~0 °C surface temperatures and are shielded from daily and annual cycles. With retreat, rock walls are rapidly exposed to strongly varying temperature boundary conditions, a transition we term “paraglacial thermal shock.” Using detailed, conceptual numerical models based on the Aletsch Glacier in Switzerland, we show that including thermomechanical stresses during simulated glacial cycles creates significantly more rock slope damage than predicted for purely mechanical ice loading and unloading. Glacier advances are especially effective in generating damage as rapid cooling drives contraction of the rock mass reducing joint normal stresses. First time exposure to annual temperature cycles during deglaciation induces a shallow damage front that follows the retreating ice margin, generating damage in a complementary process at shorter time scales. Acting on a reduced strength rock mass, modeled thermomechanical cycles enhance the development of a slope instability with similar attributes as observed in our study area. Our results demonstrate that thermomechanical stresses acting in conjunction with changing ice loads are capable of generating considerable rock slope damage with spatial and temporal patterns controlled by glacier extents.
The Circulation Response to Resolved Versus Parametrized Orographic Drag Over Complex Mountain Terrains
Authors: van Niekerk Annelize , Sandu Irina , Vosper Simon B. 
Published: September 2018

AbstractThe accuracy with which parametrizations of orographic blocking and orographic gravity wave drag (OGWD) are able to reproduce the explicitly resolved impacts on flow over complex terrain is investigated in two models: the Met Office Unified Model (MetUM) and the European Centre for Medium‐Range Weather Forecasts Integrated Forecasting System (ECMWF IFS). To this end, global and limited area short‐range forecast experiments across a range of horizontal resolutions, and their model errors relative to analyses, are assessed over two complex mountainous regions: the Himalayas and the Middle East. The impact of resolved orography on the circulation is deduced by taking the difference between high‐resolution experiments with a high (4 to 9 km) and low‐resolution (125 to 150 km) orography. This is then compared with the impact of parametrized orographic drag, deduced from global low‐resolution experiments with and without parametrized orographic drag. At resolutions ranging from tens to hundreds of kilometres, both the MetUM and ECMWF IFS exhibit too strong zonal winds relative to analyses in the lower stratosphere in the region of maximum resolved orographic gravity wave breaking, indicative of some deficiency in the parametrization of OGWD. Diagnosis of the parametrized physics and resolved dynamics tendencies across a range of OGWD parameter values reveal that this error is partly due to the manner in which the resolved dynamics interacts with the parametrized OGWD. This work introduces a method for quantifying the impacts of resolved versus parametrized orographic drag in models and highlights the importance of physics‐dynamics interactions.
Cytoplasmic localization of GRHL3 upon epidermal differentiation triggers cell shape change for epithelial morphogenesis
Authors: Kimura-Yoshida Chiharu , Mochida Kyoko , Nakaya Masa-aki , Mizutani Takeomi , Matsuo Isao 
Published: September 2018

AbstractEpithelial cell shape change is a pivotal driving force for morphogenesis of complex three-dimensional architecture. However, molecular mechanisms triggering shape changes of epithelial cells in the course of growth and differentiation have not been entirely elucidated. Grhl3 plays a crucial role as a downstream transcription factor of Wnt/β-catenin in epidermal differentiation. Here, we show Grhl3 induced large, mature epidermal cells, enriched with actomyosin networks, from embryoid bodies in vitro. Such epidermal cells were apparently formed by the simultaneous activation of canonical and non-canonical Wnt signaling pathways. A nuclear transcription factor, GRHL3 is localized in the cytoplasm and cell membrane during epidermal differentiation. Subsequently, such extranuclear GRHL3 is essential for the membrane-associated expression of VANGL2 and CELSR1. Cytoplasmic GRHL3, thereby, allows epidermal cells to acquire mechanical properties for changes in epithelial cell shape. Thus, we propose that cytoplasmic localization of GRHL3 upon epidermal differentiation directly triggers epithelial morphogenesis.
Enhanced voltage generation through electrolyte flow on liquid-filled surfaces
Authors: Fan B. , Bhattacharya A. , Bandaru P. R. 
Published: September 2018

AbstractThe generation of electrical voltage through the flow of an electrolyte over a charged surface may be used for energy transduction. Here, we show that enhanced electrical potential differences (i.e., streaming potential) may be obtained through the flow of salt water on liquid-filled surfaces that are infiltrated with a lower dielectric constant liquid, such as oil, to harness electrolyte slip and associated surface charge. A record-high figure of merit, in terms of the voltage generated per unit applied pressure, of 0.043 mV Pa−1 is obtained through the use of the liquid-filled surfaces. In comparison with air-filled surfaces, the figure of merit associated with the liquid-filled surface increases by a factor of 1.4. These results lay the basis for innovative surface charge engineering methodology for the study of electrokinetic phenomena at the microscale, with possible application in new electrical power sources.
Two coupled circadian oscillations regulate Bmal1-ELuc and Per2-SLR2 expression in the mouse suprachiasmatic nucleus
Authors: Nishide Shinya , Honma Sato , Honma Ken-ichi 
Published: September 2018

AbstractCircadian rhythms in clock genes,Bmal1andPer2expression were monitored simultaneously in the cultured slice of mouse suprachiasmatic nucleus (SCN) by dual bioluminescent reporters. In the neonatal SCN, the phase-relation between theBmal1andPer2rhythms were significantly changed during culture. Medium exchange produced phase-dependent phase shifts (PRCm) in theBmal1rhythms, but not in thePer2rhythms. As a result, the two circadian rhythms were temporally dissociated after medium exchange. In the adult SCN, the phase-relation between the two rhythms was kept constant during culture at least up to 20 cycles. The amplitude of PRCm in the adult SCN was significantly attenuated in theBmal1rhythm, whereas a PRCm was developed in thePer2rhythm. The circadian period was not systematically affected by medium exchange in either of rhythms, regardless of whether it was in the neonatal or the adult SCN. Tetrodotoxin, a sodium channel blocker, enhanced the phase-response in both rhythms but abolished the phase-dependency. In addition, tetrodotoxin lengthened the circadian period independent of the phase of administration. Thus, theBmal1andPer2rhythms in the SCN are dissociable and likely regulated by distinct circadian oscillators.Bmal1is the component of aBmal1/REV-ERBa/ROR loop andPer2aPer/Cry/BMAL1/CLOCK loop. Both loops could be molecular mechanisms of the two circadian oscillators that are coupled through the protein product ofBmal1. The coupling strength between the two oscillations depends on developmental stages.
A Comparative Study of Hummingbirds and Chickens Provides Mechanistic Insight on the Histidine Containing Dipeptide Role in Skeletal Muscle Metabolism
Authors: Dolan E. , Saunders B. , Dantas W. S. , Murai I. H. , Roschel H. , Artioli G. G. , Harris R. , Bicudo J. E. P. W. , Sale C. , Gualano B. 
Published: September 2018

AbstractHistidine containing dipeptides (HCDs) have numerous ergogenic and therapeutic properties, but their primary role in skeletal muscle remains unclear. Potential functions include pH regulation, protection against reactive oxygen/nitrogen species, or Ca2+ regulation. In recognition of the challenge of isolating physiological processes in-vivo, we employed a comparative physiology approach to investigate the primary mechanism of HCD action in skeletal muscle. We selected two avian species (i.e., hummingbirds and chickens), who represented the extremes of the physiological processes in which HCDs are likely to function. Our findings indicate that HCDs are non-essential to the development of highly oxidative and contractile muscle, given their very low content in hummingbird skeletal tissue. In contrast, their abundance in the glycolytic chicken muscle, indicate that they are important in anaerobic bioenergetics as pH regulators. This evidence provides new insights on the HCD role in skeletal muscle, which could inform widespread interventions, from health to elite performance.
moxMaple3: a Photoswitchable Fluorescent Protein for PALM and Protein Highlighting in Oxidizing Cellular Environments
Authors: Kaberniuk Andrii A. , Mohr Manuel A. , Verkhusha Vladislav V. , Snapp Erik Lee 
Published: September 2018

AbstractThe ability of fluorescent proteins (FPs) to fold robustly is fundamental to the autocatalytic formation of the chromophore. While the importance of the tertiary protein structure is well appreciated, the impact of individual amino acid mutations for FPs is often not intuitive and requires direct testing. In this study, we describe the engineering of a monomeric photoswitchable FP, moxMaple3, for use in oxidizing cellular environments, especially the eukaryotic secretory pathway. Surprisingly, a point mutation to replace a cysteine substantially improved the yield of correctly folded FP capable of chromophore formation, regardless of cellular environment. The improved folding of moxMaple3 increases the fraction of visibly tagged fusion proteins, as well as FP performance in PALM super-resolution microscopy, and thus makes moxMaple3 a robust monomeric FP choice for PALM and optical highlighting applications.
Creating a switchable optical cavity with controllable quantum-state mapping between two modes
Authors: Chimczak Grzegorz , Bartkiewicz Karol , Ficek Zbigniew , Tanaś Ryszard 
Published: September 2018

AbstractWe describe how an ensemble of four-level atoms in the diamond-type configuration can be applied to create a fully controllable effective coupling between two cavity modes. The diamond-type configuration allows one to use a bimodal cavity that supports modes of different frequencies or different circular polarisations, because each mode is coupled only to its own transition. This system can be used for mapping a quantum state of one cavity mode onto the other mode on demand. Additionally, it can serve as a fast opening high-Q cavity system that can be easily and coherently controlled with laser fields.
Activity of a novel antimicrobial peptide against Pseudomonas aeruginosa biofilms
Authors: Beaudoin Trevor , Stone Tracy A. , Glibowicka Miroslawa , Adams Christina , Yau Yvonne , Ahmadi Saumel , Bear Christine E. , Grasemann Hartmut , Waters Valerie , Deber Charles M. 
Published: September 2018

AbstractWith the increasing recognition of biofilms in human disease, the development of novel antimicrobial therapies is of critical importance. For example, in patients with cystic fibrosis (CF), the acquisition of host-adapted, chronic Pseudomonas aeruginosa infection is associated with a decline in lung function and increased mortality. Our objective was to test the in vitro efficacy of a membrane-active antimicrobial peptide we designed, termed 6K-F17 (sequence: KKKKKK-AAFAAWAAFAA-NH2), against multidrug resistant P. aeruginosa biofilms. This peptide displays high antimicrobial activity against a range of pathogenic bacteria, yet is non-hemolytic to human erythrocytes and non-toxic to human bronchial epithelial cells. In the present work, P. aeruginosa strain PAO1, and four multidrug resistant (MDR) isolates from chronically infected CF individuals, were grown as 48-hour biofilms in a static biofilm slide chamber model. These biofilms were then exposed to varying concentrations of 6K-F17 alone, or in the presence of tobramycin, prior to confocal imaging. Biofilm biovolume and viability were assessed. 6K-F17 was able to kill biofilms – even in the presence of sputum – and greatly reduce biofilm biovolume in PAO1 and MDR isolates. Strikingly, when used in conjunction with tobramycin, low doses of 6K-F17 significantly potentiated tobramycin killing, leading to biofilm destruction.
Feasibility and robustness of dynamic 18F-FET PET based tracer kinetic models applied to patients with recurrent high-grade glioma prior to carbon ion irradiation
Authors: Debus Charlotte , Afshar-Oromieh Ali , Floca Ralf , Ingrisch Michael , Knoll Maximilian , Debus Jürgen , Haberkorn Uwe , Abdollahi Amir 
Published: September 2018

AbstractThe aim of this study was to analyze the robustness and diagnostic value of different compartment models for dynamic 18F-FET PET in recurrent high-grade glioma (HGG). Dynamic 18F-FET PET data of patients with recurrent WHO grade III (n:7) and WHO grade IV (n: 9) tumors undergoing re-irradiation with carbon ions were analyzed by voxelwise fitting of the time-activity curves with a simplified and an extended one-tissue compartment model (1TCM) and a two-tissue compartment model (2TCM), respectively. A simulation study was conducted to assess robustness and precision of the 2TCM. Parameter maps showed enhanced detail on tumor substructure. Neglecting the blood volume VB in the 1TCM yields insufficient results. Parameter K1 from both 1TCM and 2TCM showed correlation with overall patient survival after carbon ion irradiation (p = 0.043 and 0.036, respectively). The 2TCM yields realistic estimates for tumor blood volume, which was found to be significantly higher in WHO IV compared to WHO III (p = 0.031). Simulations on the 2TCM showed that K1 yields good accuracy and robustness while k2 showed lowest stability of all parameters. The 1TCM provides the best compromise between parameter stability and model accuracy; however application of the 2TCM is still feasible and provides a more accurate representation of tracer-kinetics at the cost of reduced robustness. Detailed tracer kinetic analysis of 18F-FET PET with compartment models holds valuable information on tumor substructures and provides additional diagnostic and prognostic value.
Graphitic Carbon Electrodes on Flexible Substrate for Neural Applications Entirely Fabricated Using Infrared Nanosecond Laser Technology
Authors: Vomero Maria , Oliveira Ana , Ashouri Danesh , Eickenscheidt Max , Stieglitz Thomas 
Published: September 2018

AbstractNeural interfaces for neuroscientific research are nowadays mainly manufactured using standard microsystems engineering technologies which are incompatible with the integration of carbon as electrode material. In this work, we investigate a new method to fabricate graphitic carbon electrode arrays on flexible substrates. The devices were manufactured using infrared nanosecond laser technology for both patterning all components and carbonizing the electrode sites. Two laser pulse repetition frequencies were used for carbonization with the aim of finding the optimum. Prototypes of the devices were evaluatedin vitroin 30 mM hydrogen peroxide to mimic the post-surgery oxidative environment. The electrodes were subjected to 10 million biphasic pulses (39.5 μC/cm2) to measure their stability under electrical stress. Their biosensing capabilities were evaluated in different concentrations of dopamine in phosphate buffered saline solution. Raman spectroscopy and x-ray photoelectron spectroscopy analysis show that the atomic percentage of graphitic carbon in the manufactured electrodes reaches the remarkable value of 75%. Results prove that the infrared nanosecond laser yields activated graphite electrodes that are conductive, non-cytotoxic and electrochemically inert. Their comprehensive assessment indicates that our laser-induced carbon electrodes are suitable for future transfer intoin vivostudies, including neural recordings, stimulation and neurotransmitters detection.
Afar triple junction triggered by plume-assisted bi-directional continental break-up
Authors: Koptev Alexander , Gerya Taras , Calais Eric , Leroy Sylvie , Burov Evgueni 
Published: September 2018

AbstractDivergent ridge-ridge-ridge (R-R-R) triple junctions are one of the most remarkable, yet largely enigmatic, features of plate tectonics. The juncture of the Arabian, Nubian, and Somalian plates is a type-example of the early development stage of a triple junction where three active rifts meet at a ‘triple point’ in Central Afar. This structure may result from the impingement of the Afar plume into a non-uniformly stressed continental lithosphere, but this process has never been reproduced by self-consistent plume-lithosphere interaction experiments. Here we use 3D thermo-mechanical numerical models to examine the initiation of plume-induced rift systems under variable far-field stress conditions. Whereas simple linear rift structures are preferred under uni-directional extension, we find that more complex patterns form in response to bi-directional extension, combining one or several R-R-R triple junctions. These triple junctions optimize the geometry of continental break-up by minimizing the amount of dissipative mechanical work required to accommodate multi-directional extension. Our models suggest that Afar-like triple junctions are an end-member mode of plume-induced bi-directional rifting that combines asymmetrical northward pull and symmetrical EW extension at similar rates.
Superconductivity at 38 K at an electrochemical interface between an ionic liquid and FeSe0.8Te0.2 on various substrates
Authors: Kouno Shunsuke , Sato Yohei , Katayama Yumiko , Ichinose Ataru , Asami Daisuke , Nabeshima Fuyuki , Imai Yoshinori , Maeda Atsutaka , Ueno Kazunori 
Published: September 2018

AbstractSuperconducting FeSe0.8Te0.2 thin films on SrTiO3, LaAlO3 and CaF2 substrates were electrochemically etched in an ionic liquid, DEME-TFSI, electrolyte with a gate bias of 5 V. Superconductivity at 38 K was observed on all substrates after the etching of films with a thickness greater than 30 nm, despite the different Tc values of 8 K, 12 K and 19 K observed before etching on SrTiO3, LaAlO3 and CaF2 substrates, respectively. Tc returned to its original value with the removal of the gate bias. The observation of Tc enhancement for these thick films indicates that the Tc enhancement is unrelated to any interfacial effects between the film and the substrate. The sheet resistance and Hall coefficient of the surface conducting layer were estimated from the gate bias dependence of the transport properties. The sheet resistances of the surface conducting layers of the films on LaAlO3 and CaF2 showed identical temperature dependence, and the Hall coefficient was found to be almost independent of temperature and to take values of −0.05 to −0.2 m2/C, corresponding to 4–17 electrons per FeSe0.8Te0.2 unit cell area in two dimensions. These common transport properties on various substrates suggest that the superconductivity at 38 K appears in the surface conducting layer as a result of an electrochemical reaction between the surface of the FeSe0.8Te0.2 thin film and the ionic liquid electrolyte.