bluuebunny/crossref_metadata_2025_split huggingface dataset:
Answering the “why” in answer set programming – A survey of explanation approaches
Authors: FANDINNO JORGE , SCHULZ CLAUDIA 
Published: January 2019

AbstractArtificial intelligence (AI) approaches to problem-solving and decision-making are becoming more and more complex, leading to a decrease in the understandability of solutions. The European Union’s new General Data Protection Regulation tries to tackle this problem by stipulating a “right to explanation” for decisions made by AI systems. One of the AI paradigms that may be affected by this new regulation is answer set programming (ASP). Thanks to the emergence of efficient solvers, ASP has recently been used for problem-solving in a variety of domains, including medicine, cryptography, and biology. To ensure the successful application of ASP as a problem-solving paradigm in the future, explanations of ASP solutions are crucial. In this survey, we give an overview of approaches that provide an answer to the question ofwhyan answer set is a solution to a given problem, notably off-line justifications, causal graphs, argumentative explanations, and why-not provenance, and highlight their similarities and differences. Moreover, we review methods explaining why a set of literals isnotan answer set or why no solution exists at all.
Biotechnology and the lifetime of technical civilizations
Authors: Sotos John G. 
Published: January 2019

AbstractThe number of people able to end Earth's technical civilization has heretofore been small. Emerging dual-use technologies, such as biotechnology, may give similar power to thousands or millions of individuals. To quantitatively investigate the ramifications of such a marked shift on the survival of both terrestrial and extraterrestrial technical civilizations, this paper presents a two-parameter model for civilizational lifespans, i.e. the quantity L in Drake's equation for the number of communicating extraterrestrial civilizations. One parameter characterizes the population lethality of a civilization's biotechnology and the other characterizes the civilization's psychosociology. L is demonstrated to be less than the inverse of the product of these two parameters. Using empiric data from PubMed to inform the biotechnology parameter, the model predicts human civilization's median survival time as decades to centuries, even with optimistic psychosociological parameter values, thereby positioning biotechnology as a proximate threat to human civilization. For an ensemble of civilizations having some median calculated survival time, the model predicts that, after 80 times that duration, only one in 1024 civilizations will survive – a tempo and degree of winnowing compatible with Hanson's ‘Great Filter.’ Thus, assuming that civilizations universally develop advanced biotechnology, before they become vigorous interstellar colonizers, the model provides a resolution to the Fermi paradox.
BLACK PROTESTANT VIEWS OF SCIENCE
Authors: Tinsley Cleve , Prickett Pamela J. , Ecklund Elaine Howard 
Published: January 2019

AbstractWe ask how Black Protestants frame the connection between religion and science, analyzing fifty in-depth interviews with Black Protestants of different socioeconomic backgrounds who attend churches in two U.S. cities. Although individuals across the sample observe some tension, or incompatibility, between religion and science, Black Protestants from lower socioeconomic backgrounds tended to perceive much more tension when compared with those from higher socioeconomic backgrounds. However, when science is thought to contribute to improving health conditions (e.g., medical improvements to diagnose or prevent birth defects), individuals from both SES backgrounds framed religion and science as compatible. This lack of tension in regards to medicine challenges prevailing wisdom about lower-income African Americans’ attitudes towards medicine. We draw out the implications of these findings for larger discussions about trust toward science and scientific communities, elucidating Black Protestant particularities and perspectives in tensions between science and religion as a foundation for further research.
Clarifying the Relative Role of Forcing Uncertainties and Initial‐Condition Unknowns in Spreading the Climate Response to Volcanic Eruptions
Authors: Zanchettin Davide , Timmreck Claudia , Toohey Matthew , Jungclaus Johann H. , Bittner Matthias , Lorenz Stephan J. , Rubino Angelo 
Published: January 2019

AbstractRadiative forcing from volcanic aerosol impacts surface temperatures; however, the background climate state also affects the response. A key question thus concerns whether constraining forcing estimates is more important than constraining initial conditions for accurate simulation and attribution of posteruption climate anomalies. Here we test whether different realistic volcanic forcing magnitudes for the 1815 Tambora eruption yield distinguishable ensemble surface temperature responses. We perform a cluster analysis on a superensemble of climate simulations including three 30‐member ensembles using the same set of initial conditions but different volcanic forcings based on uncertainty estimates. Results clarify how forcing uncertainties can overwhelm initial‐condition spread in boreal summer due to strong direct radiative impact, while the effect of initial conditions predominate in winter, when dynamics contribute to large ensemble spread. In our setup, current uncertainties affecting reconstruction‐simulation comparisons prevent conclusions about the magnitude of the Tambora eruption and its relation to the “year without summer.”
The Changing Impact Mechanisms of a Diverse El Niño on the Western Pacific Subtropical High
Authors: Chen Mengyan , Yu Jin‐Yi , Wang Xin , Jiang Wenping 
Published: January 2019

AbstractThe composite analyses during 1950–2016 show that the impacts of El Niño on the western Pacific subtropical high (WPSH) are different among the Eastern Pacific type, Central Pacific type‐I (CP‐I), and Central Pacific type‐II (CP‐II). The three types of El Niño produce distinct impacts on WPSH due to the varying importance of the Northwestern Pacific coupling, Indian Ocean capacitor, and Maritime Continent mechanisms. The different enhancements and cancellations among these three mechanisms are related to differences in SST anomaly locations and Indian Ocean conditions among the El Niño types. The CP‐II El Niño becomes the most influential type of El Niño, while the CP‐I El Niño becomes the least influential type. The different impacts and mechanisms for the CP‐I and CP‐II types of El Niño imply that these two subtypes of CP El Niño may involve different forcing from the Indian Ocean and extratropical Pacific for their generation.
Quantifying the Role of Oceanic Feedbacks on ENSO Asymmetry
Authors: Guan Cong , McPhaden Michael J. , Wang Fan , Hu Shijian 
Published: January 2019

AbstractThe role of oceanic feedbacks in determining the asymmetry of El Niño–Southern Oscillation (ENSO) magnitude, spatial structure, and duration is quantified on the basis of a novel temperature variance budget. Results confirm previous studies that in the eastern Pacific, El Niño warm temperature anomalies are larger in magnitude than La Niña cold temperature anomalies mainly due to stronger positive oceanic feedbacks for El Niño. We find that La Niña cold anomalies are typically stronger than El Niño warm anomalies in the central Pacific with a faster growth rate for cold anomalies, due to a stronger positive thermocline feedback and weaker nonlinear damping. The thermocline feedback related to recharge oscillator dynamics plays a dominate role and leads to asymmetry in the duration of El Niño and La Niña events. In particular, the thermocline feedback becomes significantly negative during the late decaying phase of El Niño and speeds up its demise.
Regional‐Scale Detection of Fault Scarps and Other Tectonic Landforms: Examples From Northern California
Authors: Sare Robert , Hilley George E. , DeLong Stephen B. 
Published: January 2019

AbstractFault scarps and fault‐related landforms provide important information about fault zone activity over timescales that are not captured by instrumental measurements or historic records. Semiautomated methods for delineating these landforms using topographic data from light detection and ranging (lidar) and spaceborne imaging systems offer the opportunity to characterize fault zones on a global scale. We present a computationally efficient method for extracting scarp‐like landforms from high‐resolution (≤2 m), regional‐scale (≥ 100‐km‐long) digital topographic data sets. We identify fault‐related landforms using a curvature template based on the diffusion model for scarp degradation and extract scarp heights and morphologic ages at each pixel. The method was applied to the GeoEarthScope Northern California data set, an airborne lidar acquisition imaging nearly 2,500 km2 of the northern San Andreas Fault system, by adapting the algorithm to use cloud computing resources. Template results and fault trace mapping show spatial agreement in active fault zones with clear topographic expression, including detection of fault scarps, shutter ridges, and elongated drainages. Comparison of the method against field‐based morphologic dating of scarps along the southern San Andreas reveals a trade‐off between template window size and morphologic age contrasts resolved between strike‐slip fault scarps of different relative ages. Detection performance suggests that window size and orientation constraints may play a key role in improving the accuracy of methods for semiautomated fault zone mapping. As data availability grows, these methods could constrain key earthquake simulation parameters such as damage zone width or rupture length and improve fault maps worldwide.
Response of the Arctic Marine Inorganic Carbon System to Ice Algae and Under‐Ice Phytoplankton Blooms: A Case Study Along the Fast‐Ice Edge of Baffin Bay
Authors: Else Brent G. T. , Whitehead Jeremy J. , Galindo Virginie , Ferland Joannie , Mundy C. J. , Gonski Stephen F. , Ehn Jens K. , Rysgaard Søren , Babin Marcel 
Published: January 2019

AbstractPast research in seasonally ice‐covered Arctic seas has suggested that ice algae play a role in reducing dissolved inorganic carbon (DIC) during spring, preconditioning surface waters to low dissolved CO2 (pCO2sw), and uptake of atmospheric CO2 during the ice‐free season. The potential role of under‐ice phytoplankton blooms on DIC and pCO2sw has not often been considered. In this study we examined the inorganic carbon system beneath landfast sea ice starting midway through a bottom ice algae bloom and concluding in the early stages of an under‐ice phytoplankton bloom. During most of the ice algae bloom we observed a slight increase in DIC/pCO2sw in surface waters, as opposed to the expected reduction. Biomass calculations confirm that the role of ice algae on DIC/pCO2sw in the study region were minor and that this null result may be widely applicable. During snow melt, we observed an under‐ice phytoplankton bloom (to 10 mg/m3 Chl a) that did reduce DIC and pCO2sw. We conclude that under‐ice phytoplankton blooms are an important biological mechanism that may predispose some Arctic seas to act as a CO2 sink at the time of ice breakup. We also found that pCO2sw was undersaturated at the study location even at the beginning of our sampling period, consistent with several other studies that have measured under‐ice pCO2sw in late winter or early spring. Finally, we present the first measurements of carbonate saturation states for this region, which may be useful for assessing the vulnerability of a local soft‐shelled clam fishery to ocean acidification.
Why Gliders Appreciate Good Company: Glider Assimilation in the Oregon‐Washington Coastal Ocean 4DVAR System With and Without Surface Observations
Authors: Pasmans I. , Kurapov A. L. , Barth J. A. , Ignatov A. , Kosro P. M. , Shearman R. K. 
Published: January 2019

AbstractGliders are low‐power autonomous underwater vehicles used to obtain oceanic measurements in vertical sections. Assimilation of glider temperature and salinity into coastal ocean circulation models holds the potential to improve the ocean subsurface structure estimate. In this study, the impact of assimilation of glider observations is studied using a four‐dimensional variational (4DVAR) data assimilation and forecast system set offshore of Oregon and Washington on the U.S. West Coast. Four test cases are compared: (1) no assimilation, (2) assimilation of glider temperature and salinity data alone, (3) assimilation of the glider data in combination with the surface observations including satellite sea surface temperature, sea surface height, and high‐frequency radar surface velocities, and (4) assimilation of the surface data alone. It is found that the assimilation of glider observations alone creates unphysical eddies in the vicinity of the glider transect. As a consequence, the forecast errors in the surface velocity and temperature increase compared to the case without data assimilation. Assimilation of surface and subsurface observations in combination prevents these features from forming and reduces the errors in the forecasts for the subsurface fields compared to the other three experiments. These improvements persisted in 21‐day forecasts run after the last data assimilation cycle.
Advancing Short‐Term Forecasts of Ice Conditions in the Beaufort Sea
Authors: Yaremchuk M. , Townsend T. , Panteleev G. , Hebert D. , Allard R. 
Published: January 2019

AbstractNumerical experiments with a regional configuration of the CICE model (Los‐Alamos Community sea Ice CodE) in the Beaufort Sea assimilating Special Sensor Microwave Imager/Sounder ice concentration (IC) and CryoSat ice thickness (IT) data acquired for September–December of 2015 are presented. We explore sensitivity of the 24‐hr IT/IC forecast skill to the system updates, which include introduction of the IT assimilation capability, flow‐dependent correlations, and Gaussianization of IC innovations. Experiments with IC data assimilation have shown that the flow‐dependent correlations provide 5–7% improvement of the forecast skill during the freezing period (10 September to 10 November) while Gaussianization contributes an additional improvement of 3–4% in most of the cases. In winter (11 November to 31 December) IC assimilation did not produce any statistically significant improvement of the skill due to the loss of dynamical information in the IC fields associated saturation of the ice cover. In contrast, IT assimilation provides larger improvement in December compared to October–November due to the better coverage of the Beaufort Sea by observations and their higher relative accuracy in winter. Comparison of the IT forecast fields with independent in situ observations by two upward looking sonars demonstrates statistically insignificant improvements. Much better improvement (15–25%) is observed when comparing monthly mean IT assimilation runs against independent Advanced Microwave Scanning Radiometer for Earth observing system (AMSR‐E) data. Introduction of the heuristic in situ IC/IT correlations into the background covariance model did not produce any improvements of the forecast skill.
Observed and Simulated Teleconnections Between the Stratospheric Quasi‐Biennial Oscillation and Northern Hemisphere Winter Atmospheric Circulation
Authors: Andrews Martin B. , Knight Jeff R. , Scaife Adam A. , Lu Yixiong , Wu Tongwen , Gray Lesley J. , Schenzinger Verena 
Published: January 2019

AbstractThe Quasi‐Biennial Oscillation (QBO) is the dominant mode of interannual variability in the tropical stratosphere, with easterly and westerly zonal wind regimes alternating over a period of about 28 months. It appears to influence the Northern Hemisphere winter stratospheric polar vortex and atmospheric circulation near the Earth's surface. However, the short observational record makes unequivocal identification of these surface connections challenging. To overcome this, we use a multicentury control simulation of a climate model with a realistic, spontaneously generated QBO to examine teleconnections with extratropical winter surface pressure patterns. Using a 30‐hPa index of the QBO, we demonstrate that the observed teleconnection with the Arctic Oscillation (AO) is likely to be real, and a teleconnection with the North Atlantic Oscillation (NAO) is probable, but not certain. Simulated QBO‐AO teleconnections are robust, but appear weaker than in observations. Despite this, inconsistency with the observational record cannot be formally demonstrated. To assess the robustness of our results, we use an alternative measure of the QBO, which selects QBO phases with westerly or easterly winds extending over a wider range of altitudes than phases selected by the single‐level index. We find increased strength and significance for both the AO and NAO responses, and better reproduction of the observed surface teleconnection patterns. Further, this QBO metric reveals that the simulated AO response is indeed likely to be weaker than observed. We conclude that the QBO can potentially provide another source of skill for Northern Hemisphere winter prediction, if its surface teleconnections can be accurately simulated.
High‐Speed Video and Lightning Mapping Array Observations of In‐Cloud Lightning Leaders and an M Component to Ground
Authors: Kotovsky D. A. , Uman M. A. , Wilkes R. A. , Jordan D. M. 
Published: January 2019

AbstractHigh‐speed video (46,000 frames per second) and lightning‐mapping‐array (LMA) data are correlated to determine three‐dimensional properties of in‐cloud lightning leaders (altitudes ranging from 2.78 to 3.81 km) observed in a rocket‐and‐wire triggered lightning flash. Three positive leaders were observed with speeds ranging from 6.1 × 104 to 1.0 × 105 m/s, one of which branched within the camera frame. The upper branch was then traversed twice by attempted negative leaders propagating toward the main channel to ground (speeds of 2.4 × 106 and 1.1 × 107 m/s). Both attempted negative leaders terminated abruptly at the branch point of the remnant channel. In the remnants of a separate positive leader channel, a bidirectional leader initiated, which resulted in an M component whose luminosity and current were measured at ground. Analysis shows that the luminosity wave associated with the entire M component process (propagating 8.8 km from initiation to ground) is highly dispersive, with calculated group velocities ranging from 1 × 107 to 5 × 107 m/s over the dominant signal bandwidth of DC (0 Hz) to 2 kHz.
Moist Entropy and Water Isotopologues in a Zonal Overturning Circulation Framework of the Madden‐Julian Oscillation
Authors: Hurley John V. , Verlinden Kathryn L. , Blossey Peter N. , Kuang Zhiming , Noone David 
Published: January 2019

AbstractThe Madden‐Julian oscillation (MJO) is the principal source of tropical intraseasonal variability, yet challenges remain to accurately simulate its observed convective behavior and eastward propagation. There is specific need for evaluating the role of water within the MJO, including evaporation, vertical transport, precipitation, and latent heating of the coupled atmosphere‐ocean system. Hydrogen isotope ratios are particularly useful for investigating these aspects of the water cycle. This study complements previous characterization of MJO joint distributions for water vapor and isotopologue concentrations (δD) with consideration of moist entropy in the tropical zonal overturning circulation framework of the MJO. The goals are to distinguish the roles of convective and large‐scale dynamic processes through the life cycle of the MJO and identify shortcomings for modeling MJO humidity, clouds, and convection. From MJO composite analyses, wet equivalent potential temperature (θq) anomalies are largest at 500 hPa and tilt westward with altitude. A positive θq anomaly co‐occurs with the precipitation maxima, and negative θq anomalies co‐occur with subsidence both trailing and leading the convective center. Out of phase with θq, δD anomalies are positive east and negative west of the convective center, coherent with the regional zonal overturning stream function. These results point to a decoupling in the MJO between midtroposphere water vapor, which is tied to convective processes, and the isotopologue ratios, which are tied to the large‐scale circulation. A conceptual model is presented to describe the physical processes that explain the MJO life‐cycle for joint distributions of humidity (q) and water vapor δD.
A Decadal Data Set of Global Atmospheric Dust Retrieved From IASI Satellite Measurements
Authors: Clarisse L. , Clerbaux C. , Franco B. , Hadji‐Lazaro J. , Whitburn S. , Kopp A. K. , Hurtmans D. , Coheur P.‐F. 
Published: January 2019

AbstractAerosol is an important component of the Earth's atmosphere, affecting weather, climate, and diverse elements of the biosphere. Satellite sounders are an essential tool for measuring the highly variable distributions of atmospheric aerosol. Here we present a new algorithm for estimating atmospheric dust optical depths and associated retrieval uncertainties from spectral radiance measurements of the Infrared Atmospheric Sounding Interferometer (IASI). The retrieval is based on the calculation of a dust index and on a neural network trained with synthetic IASI spectra. It has an inherent high sensitivity to dust and efficiently discriminates dust from other aerosols. In particular, over remote dust‐free areas, the retrieved levels of optical depth have a low bias. Over sea, noise levels are markedly lower than over land. Performance over deserts is comparable to that of other land surfaces. We use ground‐based coarse mode aerosol measurements from the AErosol RObotic NETwork to validate the new product. The overall assessment is favorable, with standard deviations in line with estimated uncertainties, low biases, and high correlation coefficients. However, a systematic relative bias occurs between sites dominated by African and Asian dust sources respectively, likely linked to differences in mineralogy. The retrieval has been performed on over a decade of IASI data, and the resulting data set is now publicly available. We present a global seasonal dust climatology based on this record and compare it with those obtained from independent satellite measurements (Moderate Resolution Imaging Spectroradiometer and a third‐party IASI product) and dust optical depth from the ECMWF model.
Genetic basis for the establishment of endosymbiosis in Paramecium
Authors: He Ming , Wang Jinfeng , Fan Xinpeng , Liu Xiaohui , Shi Wenyu , Huang Ning , Zhao Fangqing , Miao Miao 
Published: January 2019

Abstract
The single-celled ciliate Paramecium bursaria is an indispensable model for investigating endosymbiosis between protists and green-algal symbionts. To elucidate the mechanism of this type of endosymbiosis, we combined PacBio and Illumina sequencing to assemble a high-quality and near-complete macronuclear genome of P. bursaria. The genomic characteristics and phylogenetic analyses indicate that P. bursaria is the basal clade of the Paramecium genus. Through comparative genomic analyses with its close relatives, we found that P. bursaria encodes more genes related to nitrogen metabolism and mineral absorption, but encodes fewer genes involved in oxygen binding and N-glycan biosynthesis. A comparison of the transcriptomic profiles between P. bursaria with and without endosymbiotic Chlorella showed differential expression of a wide range of metabolic genes. We selected 32 most differentially expressed genes to perform RNA interference experiment in P. bursaria, and found that P. bursaria can regulate the abundance of their symbionts through glutamine supply. This study provides novel insights into Paramecium evolution and will extend our knowledge of the molecular mechanism for the induction of endosymbiosis between P. bursaria and green algae.