bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gravitational Lensing
Authors: Refsdal Sjur , Surdej Jean 
Published: June 2019

AbstractAtmospheric lensing effects deform our view of distant objects; similarly, without any doubt, gravitational lensing perturbs our view of the distant Universe and affects our physical understanding of various classes of extragalactic objects. We summarize here part of the theoretical and observational evidences supporting these claims.After briefly reviewing the history of gravitational lenses, we recall the basic principles underlying the formation of gravitationally lensed images of distant cosmic sources. We describe a simple optical lens experiment, which was actually shown during the oral discourse, and which accounts for all types of presently known gravitational lens systems.The various optical and radio searches for new gravitational lens systems that are being carried out at major observatories are reviewed. State-of-the-art observations of selected gravitational lens systems, obtained with highly performing ground-based telescopes, are then presented. These include several examples of multiply imaged QSO images, radio rings and giant luminous arcs.Through the modeling of these enigmatic objects, we show how it is possible to weigh the mass of distant lensing galaxies as well as to probe the distribution of luminous and dark matter in the Universe. Among the astrophysical and cosmological interests of observing and studying gravitational lenses, we also discuss the possibility of deriving the value of the Hubble parameter Ho from the measurement of a time delay, and how to determine the size and structure of distant quasars via the observational study of micro-lensing effects.At the end of this paper, we conclude on how to possibly achieve major astro-physical and cosmological goals in the near future by dedicating, on a site with good atmospheric seeing conditions, a medium size (2-3 m) telescope to the photometric monitoring of the multiple images of known and suspected gravitational lens systems.
Presentation of WGRS Recommendations I to V
Authors: Guinot B. 
Published: June 2019

I start by general remarks on the background of the recommendations on space-time references which are submitted to you.The need to consider time scales in a relativistic framework appeared more than 20 years age following the progress of atomic time standards. After long discussions, this led the IAU to define, In 1976, time scales which were designated, In 1979, as Terrestrial Dynamical Time (TDT) and Barycentric Dynamical Time (TDB). But soon afterwards difficulties in the interpretation of the definitions of TDT and TDB arose. It appeared that the source of these difficulties was the lack of a global approach to space-time reference systems. This point of view, first voiced by J. Lieske, gained acceptance. At the very beginning of the work of the WGRS Sub-Groups on Frames and Origins (SGFO) and on Time (SGT), It became clear the the primary mission of the SGFO and SGT was to jointly prepare general recommendations on space-time references on which they could base their specific recommendations.
IERS Standards
Authors: McCarthy D. 
Published: June 2019

Due to weather-related travel delays Dr. McCarthy was unable to present his scheduled paper. In his absence, however, Dr. K. Yokoyama, Chairman of the International Earth Rotation Service (IERS), reported on the status of the revision of the IERS Standards carried out by McCarthy who provided the following precis.These standards are meant to be used in the reduction of observations contributed to the IERS and by those who require IERS estimates of polar motion, Universal Time and nutation to establish the most precise celestial and terrestrial reference systems. The goal of the IERS is to publish the document, an update of the previous version (McCarthy, 1989), in the beginning of 1992.
BBXRT Observations of Supernova Remnants
Authors: Petre R. , Serlemitsos P. J. , Marshall F. E. , Jahoda K. , Boldt E. A. , Holt S. S. , Mushotzky R. F. , Swank J. , Szymkowiak A.E. , Kelley R. , Smale A. , Arnaud K. , Weaver K. 
Published: June 2019

AbstractThe BBXRT observed nine supernova remnants during its nine-day flight. We present preliminary results from some of these observations, emphasizing the ability of BBXRT to perform spatially resolved spectroscopy. The improved spectral resolution and efficiency over previous instruments makes possible measurements of previously undetectable lines, and the broad bandpass allows simultaneous measurement of lines from oxygen through iron.
Assessment of the Quality of the IDT Elemental Observations
Authors: Perryman M.A.C. 
Published: June 2019

AbstractThe quasi-simultaneous measurement of the one-dimensional angular separation of stars on the sky, on both small and large angular scales, rely on the measurements made by the IDT detector, as well as on inputs from the star mapper and attitude control system. This presentation will concentrate on the results of a comparison of the results of the IDT data processing carried out by the FAST and NDAC data analysis teams. The extent to which the intensity and phase measurements agree between the two reductions, and the extent to which the differences are consistent with expected photon noise errors, will be illustrated.
The Deuterium Abundance in the Local Interstellar Medium
Authors: Linsky Jeffrey L. 
Published: June 2019

AbstractAccurate measurements of the interstellar deuterium/hydrogen ratio along different lines of sight are needed to test predictions of contemporary cosmologies. I describe our GHRS observations of the Lyman-α, 2600 Å and 2800 Å spectral regions for the spectroscopic binary system Capella, obtained with 3.57 km s resolution and high signal/noise. We are now analyzing these data to infer the column densities of H I, D I, Mg II, and Fe II along this 13 pc line of sight.
Atomic and Molecular Spectroscopic Data for Space Astronomy: Needs and Availability
Authors: Smith Peter L. 
Published: June 2019

Most of our information about the Universe comes to us in the form of photons. In order to understand the messages they carry with them, we must study the origins of the photons and work out their histories as they journeyed through space. By analysis of the events in which the photons participated, we can construct pictures of the diverse physical and chemical environments and processess occurring in the Universe and we can learn about the nature of the astrophysical entities in which the photons were created.Because many of the astronomical photons are absorbed or redirected by the Earth’s atmosphere, space-based observing techniques have been developed and refined over the past several decades. The 1990’s will see the see the launch of a number of important new space astronomy missions that will produce vast amounts of high-resolution spectral data.
Coronal Emission and Stellar Evolution
Authors: Vaiana G. S. 
Published: June 2019

Ideally one would like to understand the origin of coronal emission in the perspective of stellar evolution, including the role of convection, magnetic field, and angular momentum. Everyone agrees that all this has something to do with coronal emission, but to prove what mechanisms are operating in detail is a different matter.The study of stellar X-ray coronae started a dozen years ago with the launch of the Einstein Observatory (Vaiana et al. 1981). From the beginning it emerged a richness of data, not anticipated in the original mission plans, involving the majority of stars and ages. Since then, the major developments of stellar coronal physics based on data from Einstein and EXOSAT have been reviewed (cf. for example Rosner, Golub & Vaiana 1985; Pallavicini 1989 and reference therein). ROSAT will certainly enrich the present scenario: the improvement in coverage will eliminate some of the present biases, and the improvement in spectral resolution will contribute to a better classification of X-ray emission. Presumably, only the substantial increment in sensitivity attainable with the AXAF and XMM missions will allow other major surprises.
Streaming Motions in the Local Universe
Authors: Lahav Ofer 
Published: June 2019

AbstractDeviations from the Hubble flow directly probe of the underlying total mass distribution, assuming the gravitational instability picture. We discuss the origin of motion of the Local Group with respect to the Cosmic Background Radiation and review the peculiar velocity field deduced from distances to hundreds of elliptical and spiral galaxies, including new results for the Shapley Supercluster. Bulk-flow solutions which are free of Malmquistbias are presented, indicating coherence length larger than that expected from the optical and IRAS dipoles or from Cold Dark Matter models.
The Nasa Planetary Data System
Authors: Rahe Jurgen 
Published: June 2019

AbstractThe “Planetary Data System” (PDS) was developed and supported by the Solar System Exploration Division of the National Aeronautics and Space Administration (NASA) and has now successfully operated for a few years. Its primary objectives are to preserve data obtained from previous, current and future space missions; to help individual scientists in the analysis of planetary data by preparing them in a usable form and making them easily accessible to the community; and to assist the National Space Science Data Center (NSSDC) managing, archiving and distributing data obtained by NASA missions. The principal goals and general structure of the PDS have been summarized in several brochures issued by the PDS and articles such as e.g., “The Planetary Data System” by S.W. Lee, published in the IUGG U.S. National Report on Planetology 1987-1990 or by the Jet Propulsion Laboratory. Additional information can be obtained e.g., by the current author; the PDS Project Manager, S. McMahon at JPL; the PDS Project Scientist, S. Lee at the Laboratory for Atmospheric and Space Physics, University of Colorado or from any of the seven Discipline Nodes listed below.
Using a Feminist Paradigm (Intersectionality) to Study Conservative Women: The Case of Pro-life Activists in Italy
Authors: Avanza Martina 
Published: June 2019

AbstractThis article builds on ethnographic research concerning the Italian pro-life movement and argues for the use of intersectionality theory in studying conservative women. The article suggests, first, that understanding conservative movements necessitates linking their political claims to the social identities of their activists, as would be the case for any other social movement (e.g., feminism). These social identities are as complex and intersectional as any other: a white, upper-class pro-life activist is no less intersectional than a black feminist from a poor background. Concomitantly, there is no unique feminism, but rather a plurality of feminisms, a diversity that intersectionality facilitates the identification of. The same is true for pro-life movements, but scholars tend to use the singular form to talk about conservatism; in this article, I explore the use of the plural to show that pro-life women do not constitute a monolithic group. On the contrary, these women are diverse in terms of their reproductive stories, their working status, and their class, race, and sexual practices, and this diversity translates into different ways of being pro-life. Second, recognizing this complexity does not suggest a natural link between feminism and conservatism. Alternatively, I suggest that a better understanding of conservative women can only be reached if they are studied on their own terms.
How Did It All Begin: The Self-assembly of Organic Molecules and the Origin of Cellular Life
Authors: Deamer David W. 
Published: June 2019

Movies are the myths of late-20th century western culture. Because of the power of films likeETto capture our imagination, we are more likely than past generations to accept the possibility that life exists elsewhere in our galaxy. Such a myth can be used to sketch the main themes of this chapter, which concern the origin of life on the Earth.Imagine that 4 billion years ago, intelligent beings evolved on an Earth-like planet in the solar system of a neighboring star. After ten million years of evolution, they have solved the problems of interstellar travel and aging. Virtually immortal family groups set out to explore the galaxy and almost immediately discover a solar system associated with a nearby star only 80 light years away from their home planet. They find that the third planet is rich in the primary elements of life - carbon, hydrogen, oxygen and nitrogen - which are present in the atmosphere in the form of carbon dioxide (CO2), molecular nitrogen (N2) and water vapor (H2O). They decide to spend a few centuries studying this planet, which they consider to be a possible model of their own primordial world as it was four billion years in their past.
Effects of Aerosols on the Precipitation of Convective Clouds: A Case Study in the Yangtze River Delta of China
Authors: Liu Chong , Wang Ti‐Jian , Chen Pu‐Long , Li Meng‐Meng , Zhao Ming , Zhao Kun , Wang Ming‐Huai , Yang Xiu‐Qun 
Published: June 2019

AbstractAerosol is a critical factor affecting the atmospheric hydrological cycle and climate change. Acting as cloud condensation nuclei for cloud formation, aerosols have a significant impact on regional precipitation. This study uses the fully coupled chemistry module (Weather Research and Forecasting/Chem) within the Weather Research and Forecasting model to simulate convective cloud precipitation in the Yangtze River Delta of China. To investigate the impact of on precipitation, four numerical experiments are conducted. The base case uses the full emission inventory (which we call the 100% case), and the other three cases are designed based on reduced emissions for different percentages (which we call the 50% case, the 10% case, and the 1% case). Compared to the other cases, the grid point hour maximum precipitation of the 50% case is the largest, which can reach 44.1 mm/hr and has an increase of 5% over the 100% case. The strongest precipitation is delayed by about 1 hr in the 50% case, and precipitation area is increased by 6.5%. This study indicates that the influence of aerosols on regional precipitation is a nonlinear process, with a correlation coefficient of 0.52 (p<0.01) showing a strong positive correlation between cloud condensation nuclei (>250 cm−3, height of 0.5–3 km) and precipitation. Further analysis of the dynamics and microphysical processes of this convective precipitation shows that the 50% case has an area with higher rising velocity and bigger cloud water mixing ratio than the other cases but has a relatively low convective center. The formation of precipitation is mainly influenced by the accretion of snow by rain, but the role of the snow melting into rain cannot be ignored.
Variation of Anomalous Convergence Around Kalimantan Island in Lower Troposphere and Its Role in Connecting the East Asian Summer Monsoon and Australian Winter Monsoon
Authors: Chen Wei , Guan Zhaoyong , Xu Qi , Yang Huadong 
Published: June 2019

AbstractUsing the data from ERA‐interim, the Hadley Centre Global Sea Surface Temperature data set, and the Climate Prediction Center Merged Analysis of Precipitation, after removing the simultaneous El Niño and Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) signals, we have investigated variations of anomalous convergence around Kalimantan Island in lower troposphere in associations with the East Asian summer and Australian winter monsoons. Results indicate that when negative sea surface temperature anomalies appear in the western Pacific on both sides of the equator, the atmospheric cooling over the northwestern Pacific and from the South Pacific Convergence Zone (SPCZ) to Australia is favorable for the maintenance of anticyclonic anomalies over the areas from the western Pacific to the South China Sea and from the south of the equator to the northeast of Australia. These anomalous anticyclonic circulations can induce equatorial easterly anomalies, which subsequently facilitate the maintenance of anomalous convergence around Kalimantan Island. In turn, the anomalous convergence in Kalimantan Island is favorable for the maintenance of anomalous anticyclonic over the northwestern Pacific and SPCZ and thereby intensifies both the western Pacific subtropical high and the Australian High, inducing concurrent intensifications of the East Asian summer monsoon and Australian winter monsoon. Related to the anomalous convergence over Kalimantan Island, precipitation and temperature decrease from the western Pacific to SPCZ but increase from the Indian Ocean to western Maritime Continent and Australia, while temperature is lower than normal in Kalimantan. The above results have remarkable implications for in‐depth understanding of the mechanism behind anomalies of the East Asian summer monsoon and Australian winter monsoon.
Thermokarst Effects on Carbon Dioxide and Methane Fluxes in Streams on the Peel Plateau (NWT, Canada)
Authors: Zolkos Scott , Tank Suzanne E. , Striegl Robert G. , Kokelj Steven V. 
Published: June 2019

AbstractThermokarst can rapidly mobilize vast amounts of sediment, solutes, and organic carbon previously maintained in frozen soils to inland waters. Streams provide a critical pathway for transforming these materials into carbon dioxide (CO2) and methane (CH4), yet the direct effects of thermokarst on fluvial C gas efflux from streams to the atmosphere are largely unknown. Working on the Peel Plateau in the western Canadian Arctic, we show that CO2efflux in rill runoff thaw streams (runoff) within retrogressive thaw slumps (RTSs) was four times greater than in adjacent streams and contributed modestly but disproportionately to efflux at the landscape scale. In contrast, CH4efflux was generally greater in adjacent streams than in RTS runoff and, overall, was within the range of values reported for other northern streams. While RTS occurrence was a primary driver of CO2efflux, CH4efflux was more strongly associated with conditions reflective of biological activity. Transects downstream of two RTSs revealed that CH4consistently and rapidly degassed to the atmosphere, while elevated CO2was sustained downstream of one RTS feature. At the watershed scale, streams adjacent to RTSs rather than runoff streams within RTSs dominated fluvial CO2and CH4efflux. Intensifying thermokarst activity in the western Canadian Arctic will likely amplify contributions from runoff streams in RTSs to watershed‐scale fluvial C gas efflux.
High‐Resolution Spatial Sampling Identifies Groundwater as Driver of CO2 Dynamics in an Alpine Stream Network
Authors: Horgby Åsa , Boix Canadell Marta , Ulseth Amber J. , Vennemann Torsten W. , Battin Tom J. 
Published: June 2019

AbstractInland waters are major sources of CO2 to the atmosphere. The origin of this CO2 is often elusive, especially in high‐altitude streams that remain poorly studied at present. Here we study the spatial and seasonal variations in streamwater CO2, its potential sources and drivers in an Alpine stream network (Switzerland). High‐resolution sampling combined with stable isotope analysis and mixing models enabled us to capture the fine‐scale spatial heterogeneity in streamwater pCO2 as the stream network expanded and contracted during seasons. We identified soil respiration as a major source of CO2 to the stream. We also identified a major groundwater upwelling zone as an ecosystem “control point” that disproportionately influenced stream biogeochemistry. This was particularly pronounced when the stream network expanded during snowmelt, when it covered a five times larger area compared to winter (35,300 m2 compared to 7,100 m2). Downstream from this control point, CO2 evaded rapidly owing to high gas transfer velocity. The stream network was a net source of CO2 to the atmosphere with an average areal evasion flux of 30.1 (18.0–43.1) μmol · m‐2 · s‐1 and a total flux at network scale ranging from 237 (141–339) kg C/day in winter to 1793 (1069–2565) kg C/day during spring snowmelt. Our study highlights the role of stream network dynamics and control points for the CO2 dynamics in high‐altitude streams.
Firefighters’ absorption of PAHs and VOCs during controlled residential fires by job assignment and fire attack tactic
Authors: Fent Kenneth W. , Toennis Christine , Sammons Deborah , Robertson Shirley , Bertke Stephen , Calafat Antonia M. , Pleil Joachim D. , Wallace M. Ariel Geer , Kerber Steve , Smith Denise , Horn Gavin P. 
Published: June 2019

AbstractTo better understand the absorption of combustion byproducts during firefighting, we performed biological monitoring (breath and urine) on firefighters who responded to controlled residential fires and examined the results by job assignment and fire attack tactic. Urine was analyzed for metabolites of polycyclic aromatic hydrocarbons (PAHs) and breath was analyzed for volatile organic compounds (VOCs) including benzene. Median concentrations of PAH metabolites in urine increased from pre-firefighting to 3-h post firefighting for all job assignments. This change was greatest for firefighters assigned to attack and search with 2.3, 5.6, 3.9, and 1.4-fold median increases in pyrene, phenanthrene, naphthalene, and fluorene metabolites. Median exhaled breath concentrations of benzene increased 2-fold for attack and search firefighters (p < 0.01) and 1.4-fold for outside vent firefighters (p = 0.02). Compared to interior attack, transitional attack resulted in 50% less uptake of pyrene (p = 0.09), 36% less uptake phenanthrene (p = 0.052), and 20% less uptake of fluorene (p < 0.01). Dermal absorption likely contributed to firefighters’ exposures in this study. Firefighters’ exposures will vary by job assignment and can be reduced by employing a transitional fire attack when feasible.
Auto-encoding NMR chemical shifts from their native vector space to a residue-level biophysical index
Authors: Orlando Gabriele , Raimondi Daniele , F. Vranken Wim 
Published: June 2019

AbstractChemical shifts (CS) are determined from NMR experiments and represent the resonance frequency of the spin of atoms in a magnetic field. They contain a mixture of information, encompassing the in-solution conformations a protein adopts, as well as the movements it performs. Due to their intrinsically multi-faceted nature, CS are difficult to interpret and visualize. Classical approaches for the analysis of CS aim to extract specific protein-related properties, thus discarding a large amount of information that cannot be directly linked to structural features of the protein. Here we propose an autoencoder-based method, called ShiftCrypt, that provides a way to analyze, compare and interpret CS in their native, multidimensional space. We show that ShiftCrypt conserves information about the most common structural features. In addition, it can be used to identify hidden similarities between diverse proteins and peptides, and differences between the same protein in two different binding states.