bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solar Illumination Control of the Polar Wind
Authors: Maes L. , Maggiolo R. , De Keyser J. , André M. , Eriksson A. I. , Haaland S. , Li K. , Poedts S. 
Published: November 2017

AbstractPolar wind outflow is an important process through which the ionosphere supplies plasma to the magnetosphere. The main source of energy driving the polar wind is solar illumination of the ionosphere. As a result, many studies have found a relation between polar wind flux densities and solar EUV intensity, but less is known about their relation to the solar zenith angle at the ionospheric origin, certainly at higher altitudes. The low energy of the outflowing particles and spacecraft charging means it is very difficult to measure the polar wind at high altitudes. We take advantage of an alternative method that allows estimations of the polar wind flux densities far in the lobes. We analyze measurements made by the Cluster spacecraft at altitudes from 4 up to 20 RE. We observe a strong dependence on the solar zenith angle in the ion flux density and see that both the ion velocity and density exhibit a solar zenith angle dependence as well. We also find a seasonal variation of the flux density.
Properties of the Equatorial Magnetotail Flanks ∼50–200 RE Downtail
Authors: Artemyev A. V. , Angelopoulos V. , Runov A. , Wang C.‐P. , Zelenyi L. M. 
Published: November 2017

AbstractIn space, thin boundaries separating plasmas with different properties serve as a free energy source for various plasma instabilities and determine the global dynamics of large‐scale systems. In planetary magnetopauses and shock waves, classical examples of such boundaries, the magnetic field makes a significant contribution to the pressure balance and plasma dynamics. The configuration and properties of such boundaries have been well investigated and modeled. However, much less is known about boundaries that form between demagnetized plasmas where the magnetic field is not important for pressure balance. The most accessible example of such a plasma boundary is the equatorial boundary layer of the Earth's distant magnetotail. Rather, limited measurements since its first encounter in the late 1970s by the International Sun‐Earth Explorer‐3 spacecraft revealed the basic properties of this boundary, but its statistical properties and structure have not been studied to date. In this study, we use Geotail and Acceleration, Reconnection, Turbulence and Electrodynamics of the Moon's Interaction with the Sun (ARTEMIS) missions to investigate the equatorial boundary layer from lunar orbit (∼55 Earth radii, RE, downtail) to as far downtail as ∼200 RE. Although the magnetic field has almost no effect on the structure of the boundary layer, the layer separates well the hot, rarefied plasma sheet from dense cold magnetosheath plasmas. We suggest that the most important role in plasma separation is played by polarization electric fields, which modify the efficiency of magnetosheath ion penetration into the plasma sheet. We also show that the total energies (bulk flow plus thermal) of plasma sheet ions and magnetosheath ions are very similar; that is, magnetosheath ion thermalization (e.g., via ion scattering by magnetic field fluctuations) is sufficient to produce hot plasma sheet ions without any additional acceleration.
Monte Carlo Approach for Estimating Density and Atomic Number From Dual‐Energy Computed Tomography Images of Carbonate Rocks
Authors: Victor Rodolfo A. , Prodanović Maša , Torres‐Verdín Carlos 
Published: November 2017

AbstractWe develop a new Monte Carlo‐based inversion method for estimating electron density and effective atomic number from 3‐D dual‐energy computed tomography (CT) core scans. The method accounts for uncertainties in X‐ray attenuation coefficients resulting from the polychromatic nature of X‐ray beam sources of medical and industrial scanners, in addition to delivering uncertainty estimates of inversion products. Estimation of electron density and effective atomic number from CT core scans enables direct deterministic or statistical correlations with salient rock properties for improved petrophysical evaluation; this condition is specifically important in media such as vuggy carbonates where CT resolution better captures core heterogeneity that dominates fluid flow properties. Verification tests of the inversion method performed on a set of highly heterogeneous carbonate cores yield very good agreement with in situ borehole measurements of density and photoelectric factor.
Seasonality of Formic Acid (HCOOH) in London during the ClearfLo Campaign
Authors: Bannan Thomas J. , Murray Booth A. , Le Breton Michael , Bacak Asan , Muller Jennifer B. A. , Leather Kimberley E. , Khan M. Anwar H. , Lee James D. , Dunmore Rachel E. , Hopkins James R. , Fleming Zoë L. , Sheps Leonid , Taatjes Craig A. , Shallcross Dudley E. , Percival Carl J. 
Published: November 2017

AbstractFollowing measurements in the winter of 2012, formic acid (HCOOH) and nitric acid (HNO3) were measured using a chemical ionization mass spectrometer (CIMS) during the Summer Clean Air for London (ClearfLo) campaign in London, 2012. Consequently, the seasonal dependence of formic acid sources could be better understood. A mean formic acid concentration of 1.3 ppb and a maximum of 12.7 ppb was measured which is significantly greater than that measured during the winter campaign (0.63 ppb and 6.7 ppb, respectively). Daily calibrations of formic acid during the summer campaign gave sensitivities of 1.2 ion counts s−1 parts per trillion (ppt) by volume−1 and a limit of detection of 34 ppt. During the summer campaign, there was no correlation between formic acid and anthropogenic emissions such as NOx and CO or peaks associated with the rush hour as was identified in the winter. Rather, peaks in formic acid were observed that correlated with solar irradiance. Analysis using a photochemical trajectory model has been conducted to determine the source of this formic acid. The contribution of formic acid formation through ozonolysis of alkenes is important but the secondary production from biogenic VOCs could be the most dominant source of formic acid at this measurement site during the summer.
A Case Study in Low Aerosol Number Concentrations Over the Eastern North Atlantic: Implications for Pristine Conditions in the Remote Marine Boundary Layer
Authors: Pennypacker Sam , Wood Robert 
Published: November 2017

AbstractWe present a case study (20 September to 13 October 2015) of synergistic, multi‐instrument observations of aerosols, clouds, and the marine boundary layer (MBL) at the Eastern North Atlantic (ENA) Atmospheric Radiation Measurement site centered on a period of exceptionally low (20–50 cm−3) surface accumulation mode (0.1–1 μm) aerosol particle number concentrations. We divide the case study into three regimes (high, clean, and ultraclean) based on daily median number concentrations and compare finer resolution (hourly or less) observations between these regimes. The analysis focuses on the possibility of using these ultraclean events to study pristine conditions in the remote MBL, as well as examining evidence for a recently proposed conceptual model for the large‐scale depletion of cloud condensation nuclei‐sized particles in postfrontal air masses. Relative to the high and clean regimes, the ultraclean regime tends to exhibit significantly fewer particles between 0.1 and 0.4 μm in diameter and a relatively increased prevalence of larger accumulation mode particles. In addition, supermicron particles tend to dominate total scattering in the ultraclean regime, and there is little evidence for absorbing aerosol. These observations are more in‐line with a heavily scavenged but natural marine aerosol population and minimal contribution from continental sources such as anthropogenic pollution, biomass burning, or dust. The air masses with the consistently lowest accumulation mode aerosol number concentrations are largely dominated by heavily drizzling clouds with high liquid water path cores, deep decoupled boundary layers, open cellular organization, and notable surface forcing of subcloud turbulence, even at night.
On the Origins of Mars' Exospheric Nonthermal Oxygen Component as Observed by MAVEN and Modeled by HELIOSARES
Authors: Leblanc F. , Chaufray J. Y. , Modolo R. , Leclercq L. , Curry S. , Luhmann J. , Lillis R. , Hara T. , McFadden J. , Halekas J. , Schneider N. , Deighan J. , Mahaffy P. R. , Benna M. , Johnson R. E. , Gonzalez‐Galindo F. , Forget F. , Lopez‐Valverde M. A. , Eparvier F. G. , Jakosky B. 
Published: November 2017

AbstractThe first measurements of the emission brightness of the oxygen atomic exosphere by Mars Atmosphere and Volatile EvolutioN (MAVEN) mission have clearly shown that it is composed of a thermal component produced by the extension of the upper atmosphere and of a nonthermal component. Modeling these measurements allows us to constrain the origins of the exospheric O and, as a consequence, to estimate Mars' present oxygen escape rate. We here propose an analysis of three periods of MAVEN observations based on a set of three coupled models: a hybrid magnetospheric model (LATmos HYbrid Simulation (LatHyS)), an Exospheric General Model (EGM), and the Global Martian Circulation model of the Laboratoire de Météorologie Dynamique (LMD‐GCM), which provide a description of Mars' environment from the surface up to the solar wind. The simulated magnetosphere by LatHyS is in good agreement with MAVEN Plasma and Field Package instruments data. The LMD‐GCM modeled upper atmospheric profiles for the main neutral and ion species are compared to Neutral Gas and Ion Mass Spectrometer/MAVEN data showing that the LMD‐GCM can provide a satisfactory global view of Mars' upper atmosphere. Finally, we were able to reconstruct the expected emission brightness intensity from the oxygen exosphere using EGM. The good agreement with the averaged measured profiles by Imaging Ultraviolet Spectrograph during these three periods suggests that Mars' exospheric nonthermal component can be fully explained by the reactions of dissociative recombination of the O2+ ion in Mars' ionosphere, limiting significantly our ability to extract information from MAVEN observations of the O exosphere on other nonthermal processes, such as sputtering.
The Vertical Dust Profile Over Gale Crater, Mars
Authors: Guzewich Scott D. , Newman C. E. , Smith M. D. , Moores J. E. , Smith C. L. , Moore C. , Richardson M. I. , Kass D. , Kleinböhl A. , Mischna M. , Martín‐Torres F. J. , Zorzano‐Mier M.‐P. , Battalio M. 
Published: November 2017

AbstractWe create a vertically coarse, but complete, profile of dust mixing ratio from the surface to the upper atmosphere over Gale Crater, Mars, using the frequent joint atmospheric observations of the orbiting Mars Climate Sounder (MCS) and the Mars Science Laboratory Curiosity rover. Using these data and an estimate of planetary boundary layer (PBL) depth from the MarsWRF general circulation model, we divide the vertical column into three regions. The first region is the Gale Crater PBL, the second is the MCS‐sampled region, and the third is between these first two. We solve for a well‐mixed dust mixing ratio within this third (middle) layer of atmosphere to complete the profile. We identify a unique seasonal cycle of dust within each atmospheric layer. Within the Gale PBL, dust mixing ratio maximizes near southern hemisphere summer solstice (Ls = 270°) and minimizes near winter solstice (Ls = 90–100°) with a smooth sinusoidal transition between them. However, the layer above Gale Crater and below the MCS‐sampled region more closely follows the global opacity cycle and has a maximum in opacity near Ls = 240° and exhibits a local minimum (associated with the “solsticial pause” in dust storm activity) near Ls = 270°. With knowledge of the complete vertical dust profile, we can also assess the frequency of high‐altitude dust layers over Gale. We determine that 36% of MCS profiles near Gale Crater contain an “absolute” high‐altitude dust layer wherein the dust mixing ratio is the maximum in the entire vertical column.
Mid‐Piacenzian Variability of Nordic Seas Surface Circulation Linked to Terrestrial Climatic Change in Norway
Authors: Panitz Sina , De Schepper Stijn , Salzmann Ulrich , Bachem Paul E. , Risebrobakken Bjørg , Clotten Caroline , Hocking Emma P. 
Published: November 2017

AbstractDuring the mid‐Piacenzian, Nordic Seas sea surface temperatures (SSTs) were higher than today. While SSTs provide crucial climatic information, on their own they do not allow a reconstruction of potential underlying changes in water masses and currents. A new dinoflagellate cyst record for Ocean Drilling Program (ODP) Site 642 is presented to evaluate changes in northward heat transport via the Norwegian Atlantic Current (NwAC) between 3.320 and 3.137 Ma. The record is compared with vegetation and SST reconstructions from Site 642 and SSTs from Iceland Sea ODP Site 907 to identify links between SSTs, ocean currents, and vegetation changes. The dinocyst record shows that strong Atlantic water influence via the NwAC corresponds to higher‐than‐present SSTs and cool temperate vegetation during Marine Isotope Stage (MIS) transition M2–M1 and KM5. Reduced Atlantic water inflow relative to the warm stages coincides with near‐modern SSTs and boreal vegetation during MIS M2, KM6, and KM4–KM2. During most of the studied interval, a strong SST gradient between Sites 642 and 907 indicates the presence of a proto‐Arctic Front (AF). An absent gradient during the first half of MIS KM6, due to reduced Atlantic water influence at Site 642 and warm, presumably Atlantic water reaching Site 907, is indicative of a weakened NwAC and East Greenland Current. We conclude that repeated changes in Atlantic water influence directly affect terrestrial climate and that an active NwAC is needed for an AF to develop. Obliquity forcing may have played a role, but the correlation is not consistent.
Respiratory Syncytial Virus
Authors: Melero José A , Trento Alfonsina , Mas Vicente 
Published: November 2017

AbstractHuman respiratory syncytial virus (hRSV) is the leading cause of acute lower respiratory infections in infants and young children worldwide. Epithelial cells lining the nasal passages and respiratory tract are the primary target of hRSV infection. Replication of hRSV in the host cell follows the general strategy of theMononegavirales. Cells respond to hRSV infection by producing a variety of cytokines, chemokines and interferons that are involved in the host inflammatory response. Although primary hRSV infection occurs at an early age, immunity is short‐lived or incomplete and reinfections occur throughout life. In fact, hRSV is also a pathogen of major importance for the elderly and immunocompromised adults. Initial efforts to develop a vaccine based on formalin‐inactivated virus resulted in vaccine‐enhanced disease after natural infection. However, recent advances on hRSV immunobiology have brought effective vaccines and antivirals as realistic objectives in a foreseeable future.Key ConceptsHuman respiratory syncytial virus (hRSV) is the leading cause of serious respiratory tract disease in children and infants worldwide but also a pathogen of recognised importance in the elderly and immunocompromised adults.hRSV belongs to theOrthopneumovirusgenus of thePneumoviridaefamily within theMononegaviralesorder of negative‐strand RNA viruses.The hRSV genome comprises 10 genes that encode 11 viral proteins.hRSV derives its name from the formation of multinucleated, fused cells (syncytia), which are the hallmark of infection of cultured cells or lung tissue.Following attachment to the target cell, entry by hRSV is mediated by fusion of the viral envelope with the host cell plasma membrane at neutral pH.The entire replication cycle of hRSV takes place in the cytoplasm of the infected cell.Reverse genetics has permitted the recovery of infectious hRSV from complementary DNA.hRSV strains disseminate rapidly worldwide, accumulating mutations predominantly in the attachment protein.Pathology associated with hRSV infections is not only the result of direct virus injury, but largely the consequence of an aberrant immune/inflammatory response.Palivizumab, a neutralising monoclonal antibody directed against the hRSV fusion protein, is the only product available in the market for specific prophylactic treatment of children at high risk of severe infection.
Eye: Proteomics
Authors: Sharma Tasneem P , Clark Abbot F 
Published: November 2017

Abstract

Vision is our most precious sense, and numerous ocular diseases, such as age‐related macular degeneration, glaucoma and diabetic retinopathy, are responsible for visual impairment and blindness in hundreds of millions of individuals worldwide. In the past several years, a number of advances have been made to better understand ocular biology and diseases. Research in ocular proteomics of ocular tissues and cells, such as the trabecular meshwork, retina, optic nerve head, retinal pigment epithelium, cornea, lens, sclera, tears, aqueous humour and vitreous humour, has allowed the identification of eye proteins and protein modifications that are involved in ocular development, ageing and disease. Proteomics allows biologically relevant targeting of disease diagnosis, prognosis and drug‐response evaluations. This provides an important foundation for better understanding of ocular biology and disease pathogenesis.

Key Concepts

The eye is a unique sensory organ.

A wide variety of proteomics techniques are being used to identify proteins and protein modifications that are involved in ocular development, ageing and a wide variety of ocular diseases.

Eye proteomics can be very challenging due to the very limited quantity of ocular tissues and fluids available for analysis.

Posttranslational protein modifications are commonly associated with a variety of ocular diseases, such as glaucoma, macular degeneration and cataracts.

Serum proteomics is being used to examine systemic effects of specific ocular diseases.

Proteomics studies have been performed with ocular fluids such as tears, aqueous humour and vitreous humour.

Proteomics‐based technologies allow for the development of biological and clinical ocular therapeutics.

Biomarker identification allows for determining reasonable stages of disease progression.
Minimal mask immobilization with optical surface guidance for head and neck radiotherapy
Authors: Zhao Bo , Maquilan Genevieve , Jiang Steve , Schwartz David L. 
Published: November 2017

AbstractPurposeFull face and neck thermoplastic masks provide standard‐of‐care immobilization for patients receiving H&N IMRT. However, these masks are uncomfortable and increase skin dose. The purpose of this pilot trial was to investigate the feasibility and setup accuracy of minimal face and neck mask immobilization with optical surface guidance.MethodsTwenty patients enrolled onto this IRB‐approved protocol. Patients were immobilized with masks securing only forehead and chin. Shoulder movement was restricted by either moldable cushion or hand held strap retractors. Positional information, including isocenter location and CT skin contours, were imported to a commercial surface image guidance system. Patients typically received standard‐of‐care IMRT to 60–70 Gy in 30–33 fractions. Patients were first set up to surface markings with optical image guidance referenced to regions of interest (ROIs) on simulation CT images. Positioning was confirmed by in‐room CBCT. Following six‐dimensional robotic couch correction, a new optical real‐time surface image was acquired to track intrafraction motion and to serve as a reference surface for setup at the next treatment fraction. Therapists manually recorded total treatment time as well as couch shifts based on kV imaging. Intrafractional ROI motion tracking was automatically recorded by the optical image guidance system. Patient comfort was assessed by self‐administered surveys.ResultsSetup error was measured as six‐dimensional shifts (vertical/longitudinal/lateral/rotation/pitch/roll). Mean error values were −0.51 ± 2.42 mm, −0.49 ± 3.30 mm, 0.23 ± 2.58 mm, −0.15 ± 1.01o, −0.02 ± 1.19o, and 0.06 ± 1.08o, respectively. Average treatment time was 21.6 ± 8.4 mins). Subjective comfort during surface‐guided treatment was confirmed on patient surveys.ConclusionThese pilot results confirm feasibility of minimal mask immobilization combined with commercially available optical image guidance. Patient acceptance of minimal mask immobilization has been encouraging. Follow‐up validation, with direct comparison to standard mask immobilization, appears warranted.
3D Maskless Micropatterning for Regeneration of Highly Organized Tubular Tissues
Authors: Ma Chi , Qu Tiejun , Chang Bei , Jing Yan , Feng Jerry Q. , Liu Xiaohua 
Published: November 2017

AbstractMicropatterning is a widely used powerful tool to create highly ordered microstructures on material surfaces. However, due to technical limitations, the integration of micropatterned microstructures into bioinspired 3D scaffolds to successfully regenerate well‐organized functional tissues is not achieved. In this work, a unique maskless micropatterning technology is reported to create 3D nanofibrous matrices with highly organized tubular architecture for tissue regeneration. This micropatterning method is a laser‐guided, noncontact, high‐precision, flexible computer programming of machining process that can create highly ordered tubules with the density ranged from 1000 to 60 000 mm−2 and the size varied from 300 nm to 30 µm in the bioinspired 3D matrix. The tubular architecture presents pivotal biophysical cues to control dental pulp stem cell alignment, migration, polarization, and differentiation. More importantly, when using this 3D tubular hierarchical matrix as a scaffold, this study successfully regenerates functional tubular dentin that has the same well‐organized microstructure as its natural counterpart. This 3D maskless micropattern approach represents a powerful avenue not only for the exploration of cell–material interactions in 3D, but also for the regeneration of functional tissues with well‐organized microstructures.
Placental Drug Transport‐on‐a‐Chip: A Microengineered In Vitro Model of Transporter‐Mediated Drug Efflux in the Human Placental Barrier
Authors: Blundell Cassidy , Yi Yoon‐Suk , Ma Lin , Tess Emily R. , Farrell Megan J. , Georgescu Andrei , Aleksunes Lauren M. , Huh Dongeun 
Published: November 2017

AbstractThe current lack of knowledge about the effect of maternally administered drugs on the developing fetus is a major public health concern worldwide. The first critical step toward predicting the safety of medications in pregnancy is to screen drug compounds for their ability to cross the placenta. However, this type of preclinical study has been hampered by the limited capacity of existing in vitro and ex vivo models to mimic physiological drug transport across the maternal–fetal interface in the human placenta. Here the proof‐of‐principle for utilizing a microengineered model of the human placental barrier to simulate and investigate drug transfer from the maternal to the fetal circulation is demonstrated. Using the gestational diabetes drug glyburide as a model compound, it is shown that the microphysiological system is capable of reconstituting efflux transporter‐mediated active transport function of the human placental barrier to limit fetal exposure to maternally administered drugs. The data provide evidence that the placenta‐on‐a‐chip may serve as a new screening platform to enable more accurate prediction of drug transport in the human placenta.