bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Boston University Twin Project (BUTP) II
Authors: Saudino Kimberly J. , Ganiban Jody M. 
Published: September 2019

AbstractThe Boston University Twin Project (BUTP) uses a multimethod, longitudinal approach to study the role of genetic and environmental factors on the development of child temperament and related behaviors in early childhood. There are two phases in this project. The first, described in the previous Twin Research and Human Genetics special issue on twin registries, focused on activity level and comprised over 300 twin pairs assessed in the home and laboratory at ages 2 and 3. In this article, we describe subject recruitment, sample characteristics, and study procedures and measures of the second phase of the BUTP. This recent study focuses more broadly on the development of multiple temperament dimensions and explores associations between temperament trajectories, parenting and child adjustment in a new cohort of approximately 300 twin pairs assessed at 3, 4 and 5 years of age.
Vertical Dependence of Horizontal Scaling Behavior of Orographic Wind and Moisture Fields in Atmospheric Models
Authors: Eghdami M. , Barros A. P. 
Published: September 2019

AbstractPrevious work showed that atmospheric model simulations exhibit different scaling behavior of vertically averaged horizontal wind (u,v) and moisture (q) in the mesoscales for convective (spectral slopes β~−5/3) and nonconvective (β~−11/5) conditions. Here, the focus is on the transient behavior of horizontal scaling in the vertical during the evolution of extreme orographic precipitation storms in middle (Appalachians, <2,500m) and high mountains (Andes). The results show that β exhibits a strong diurnal cycle switching between convective and nonconvective behavior following the space‐time evolution of atmospheric stability in the lower troposphere (below 700 hPa) depending on latitude, topography, landform, and the synoptic environment. Anomalous flattening of the wind and moisture spectra (i.e., spectral saturation, ∣β ∣ < 5/3) at high wavenumbers and up to 200 hPa is tied to convective activity, where and when strong vertical motions develop, corresponding to an abrupt directional switch from horizontal energy transfer to vertical energy transfer including latent heating release and parameterized microphysical processes. In the small mesoscales (<50 km), β~ − 5/3 at all times up to 200 hPa with nighttime steepening (β~−11/5) below the orographic envelope where cold air pools form at low elevations and vertical motion weakens in the Appalachians. In the Andes, the scaling behavior exhibits a stronger diurnal cycle at low levels (below 700 hPa) with significant shoaling between tropical and high latitudes. Blocking and strong modification of regional circulations result in nighttime anisotropy at midlevels on the altitudinal profile along the North‐South topographic divide.
A Modified Least Square Harmonics Estimation Method and Comparative Analysis of Established Full Periodicity Models
Authors: Zhou X. , Yang Y. , Chen H. , Ouyang W. , Fan W. 
Published: September 2019

AbstractUnmodelled periodicities of GNSS coordinate time series lead to colored noise and therefore, unreal estimations of uncertainties and misinterpretation of geophysical phenomena. This paper firstly conducted Least Square Harmonics Estimation (LSHE) and Lomb‐Scargle periodogram method respectively on 25 CMONOC GNSS time series in Yunnan Province, China to establish the corresponding function models for each station. However, several prominent problems emerge: (1) design matrix singularity occurs when too close alternative frequencies are introduced; (2) low frequencies would be missed due to the cutoff of alternative frequencies. Consequently, periodic variations of a station would be depicted in an incorrect way. In order to solve these problems, this paper proposes a method that takes advantages of both LSHE and Lomb‐Scargle periodogram, that is, (1) to conduct an examination on the reciprocal of condition number of design matrix to avoid singularity problem, (2) to introduce the frequency results from the periodogram as a priori candidate frequencies to include low frequencies and improve accuracy of alternative frequencies. Compared with LSHE method and Lomb‐Scargle periodogram, the modified LSHE method reduces Root Mean Square (RMS) value of residuals by 0.83 mm and 0.43 mm, and reduces absolute spectrum indices of residuals by 0.11 and 0.04. Spectrum analysis and auto‐correlation function of residuals indicates corresponding residuals are closer to white noise, indicating modified LSHE method of this paper is valid to reduce colored noise through establishing a full periodicity model.
Wind‐Forced Symmetric Instability at a Transient Mid‐Ocean Front
Authors: Yu Xiaolong , Naveira Garabato Alberto C. , Martin Adrian P. , Gwyn Evans D. , Su Zhan 
Published: September 2019

AbstractMooring and glider observations and a high‐resolution satellite sea surface temperature image reveal features of a transient submesoscale front in a typical mid‐ocean region of the Northeast Atlantic. Analysis of the observations suggests that the front is forced by downfront winds and undergoes symmetric instability, resulting in elevated upper‐ocean kinetic energy, restratification, and turbulent dissipation. The instability is triggered as downfront winds act on weak upper‐ocean vertical stratification and strong lateral stratification produced by mesoscale frontogenesis. The instability's estimated rate of kinetic energy extraction from the front accounts for the difference between the measured rate of turbulent dissipation and the predicted contribution from one‐dimensional scalings of buoyancy‐ and wind‐driven turbulence, indicating that the instability underpins the enhanced dissipation. These results provide direct evidence of the occurrence of symmetric instability in a quiescent open‐ocean environment and highlight the need to represent the instability's restratification and dissipative effects in climate‐scale ocean models.
Using Machine Learning to Automatically Detect Volcanic Unrest in a Time Series of Interferograms
Authors: Gaddes M. E. , Hooper A. , Bagnardi M. 
Published: September 2019

AbstractThe latest generation of synthetic aperture radar satellites produce measurements of ground deformation at the majority of the world's subaerial active volcanoes and can be used to detect signs of volcanic unrest. We present an automatic detection algorithm that uses these data to automatically warn when deformation at a volcano departs from the background. We demonstrate our approach on synthetic data sets and the unrest leading to the 2018 eruption of Sierra Negra (Galapagos). Our algorithm encompasses spatial independent component analysis and uses a significantly improved version of the ICASO algorithm, which we term ICASAR, to robustly perform spatial independent component analysis. We use ICASAR to isolate signals of geophysical interest from atmospheric signals, before monitoring the evolution of these signals through time in order to detect the onset of a period of volcanic unrest.
Saturation Hysteresis Effects on the Seismic Signatures of Partially Saturated Heterogeneous Porous Rocks
Authors: Solazzi Santiago G. , Guarracino Luis , Rubino J. Germán , Holliger Klaus 
Published: September 2019

AbstractExperimental evidence indicates that the spatial distribution of immiscible pore fluids in partially saturated media depends on the flow history and, thus, exhibits hysteresis effects. To date, most works concerned with modelling the effective seismic properties of partially saturated rocks either disregard these effects or account for them employing oversimplified approaches. This, in turn, can lead to erroneous interpretations of the corresponding seismic signatures. In this work, we present a novel methodology that allows to compute hysteresis effects on seismic attenuation and velocity dispersion due to mesoscopic wave‐induced fluid flow in realistic scenarios. For this purpose, we first employ a constitutive model that conceptualizes a porous medium as a bundle of constrictive capillary tubes with a fractal pore‐size distribution, which allows to estimate local hydraulic properties and capillary pressure‐saturation hysteretic relationships in a heterogeneous rock sample. Then, we use a numerical upscaling procedure based on Biot's poroelasticity theory to compute seismic attenuation and velocity dispersion curves during drainage and imbibition cycles. By combining these procedures, we are able to model, for the first time, key features of the saturation field and of the seismic signatures commonly observed in the laboratory during drainage and imbibition experiments. Our results also show that the pore‐scale characteristics of a given porous medium, such as the pore‐throat geometry, can greatly influence the hysteresis effects on the seismic signatures.
Evidence for a Deep Hydrologic Cycle on Oceanic Transform Faults
Authors: Kohli Arjun H. , Warren Jessica M. 
Published: September 2019

AbstractOceanic transform faults represent abundant yet relatively unexplored components of the hydrologic cycle in the mantle lithosphere. Current models limit fluid circulation to 600 °C, the thermal limit of earthquakes recorded by teleseismic surveys. However, recent ocean‐bottom seismic surveys have located earthquakes at depths corresponding to >1000 °C in modeled thermal structure. To constrain the depth extent of brittle deformation and fluid infiltration, we analyzed peridotite mylonites dredged from the Shaka Transform Fault, Southwest Indian Ridge. Samples range from high strain mylonites that preserve ductile microstructures to lower strain mylonites that are fractured and overprinted by hydrothermal alteration. Microstructural analysis of the high strain samples reveals brittle deformation of pyroxene concomitant with ductile deformation of olivine and growth of amphibole. Porphyroclasts preserve healed fractures filled with fluid inclusions, implying repeated episodes of fracture, fluid infiltration, and healing. The association of hydration features with brittle structures points to seawater, rather than melt, as the fluid source. Textural analysis indicates that strain localization was initiated by grain boundary pinning and that olivine grain size was reduced to ~1 μm in the presence of amphibole. Comparing the amphibole stability field to thermometry estimates for the limit of recrystallization suggests that fluid flow extended to ~650–850 °C. Our results indicate that the hydrologic cycle extends past the brittle‐ductile transition and promotes strain localization via hydrolytic weakening and hydration reactions. We propose that seawater infiltration on oceanic transform faults is driven by the seismic cycle and represents a first order control on the rheology of the oceanic lithosphere.
Fracture Unclogging: A Numerical Study of Seismically Induced Viscous Shear Stresses in Fluid‐Saturated Fractured Rocks
Authors: Barbosa Nicolás D. , Hunziker Jürg , Lissa Simón , Saenger Erik H. , Lupi Matteo 
Published: September 2019

AbstractDynamic shaking imposed by passing seismic waves is able to promote various hydrological processes in fractured reservoirs. This is often associated with seismically induced fracture unclogging due to mobilization of deposited colloids in the fracture network which, in turn, affects permeability at the reservoir scale. Numerous laboratory and field studies pointed out that fracture unclogging can be initiated when viscous shear stresses in the fracture fluid are in the range of 0.1–1 Pa. In this numerical study, we compute viscous shear stress in a fluid‐saturated fractured medium due to the action of passing P and S waves. We perform a sensitivity analysis in terms of fluid, fracture, and host rock physical properties as well as seismic wave characteristics. Our results show that seismically induced viscous shearing increases with frequency and seismic strain and can be in the order of those initiating fracture unclogging for typical seismic strains and frequencies. S waves tend to produce viscous shearing approximately 2 times larger than P waves, and, for anisotropic distribution of fractures, it is extremely dependent on the direction of wave propagation. Moreover, larger viscous shearing is expected for more viscous fluids and stiffer host rocks. Regarding the fracture network distribution, for the same fracture density, the presence of longer fractures drastically increases the potential of fracture unclogging at seismic frequencies. The fracture aperture distribution, on the other hand, can also affect the development of viscous shearing. Fractures with correlated distributions of contact areas exhibit an order of magnitude larger viscous shearing than uncorrelated ones.
Dynamic Rupture Simulations of the 2008 Mw 7.9 Wenchuan Earthquake by the Curved Grid Finite‐Difference Method
Authors: Zhang Zhenguo , Zhang Wenqiang , Chen Xiaofei 
Published: September 2019

AbstractEnough investigations and observations have been undertaken to suggest that the great 2008 Mw 7.9 Wenchuan earthquake of China ruptured in a highly complex pattern. The causative fault of the Wenchuan earthquake has a complex geometry, divided into several segments with offsets of a few kilometers. Modeling the dynamic rupture of this earthquake with geometrical complexity is a challenge. In this work, we simulated the dynamic rupture on the geometrically complex fault of the 2008 Mw 7.9 Wenchuan earthquake of China by the curved grid finite‐difference method. In our modeling, a uniform background tectonic stress field with tapering at shallow depth and slip‐weakening law with homogeneous friction coefficients are utilized. We found that the typical heterogeneous spatial distribution of the final seismic slip on the fault can be generated by the nonplanar complex geometry of the fault plane. Moreover, we discussed the geometrical effects of the Wenchuan earthquake on the rupture dynamics and strong ground motion. We found that the complexity of fault geometry results in the rupture complexity of the great Wenchuan earthquake. This work provides us with a new insight into the rupture dynamics of the Wenchuan earthquake.
High‐Frequency CO2 System Variability Over the Winter‐to‐Spring Transition in a Coastal Plain Estuary
Authors: Shadwick Elizabeth H. , Friedrichs Marjorie A. M. , Najjar Raymond G. , De Meo Olivia A. , Friedman Jaclyn R. , Da Fei , Reay William G. 
Published: September 2019

AbstractUnderstanding the vulnerability of estuarine ecosystems to anthropogenic impacts requires a quantitative assessment of the dynamic drivers of change to the carbonate (CO2) system. Here we present new high‐frequency pH data from a moored sensor. These data are combined with discrete observations to create continuous time series of total dissolved inorganic carbon (TCO2), CO2 partial pressure (pCO2), and carbonate saturation state. We present two deployments over the winter‐to‐spring transition in the lower York River (where it meets the Chesapeake Bay mainstem) in 2016/2017 and 2017/2018. TCO2 budgets with daily resolution are constructed, and contributions from circulation, air‐sea CO2 exchange, and biology are quantified. We find that TCO2 is most strongly influenced by circulation and biological processes; pCO2 and pH also respond strongly to changes in temperature. The system transitions from autotrophic to heterotrophic conditions multiple times during both deployments; the conventional view of a spring bloom and subsequent summer production followed by autumn and winter respiration may not apply to this region. Despite the dominance of respiration in winter and early spring, surface waters were undersaturated with respect to atmospheric CO2 for the majority of both deployments with mean fluxes ranging from −9 to −5 mmol C·m−2·day−1. Deployments a year apart indicate that the seasonal transition in the CO2 system differs significantly from one year to the next and highlights the necessity of sustained monitoring in dynamic nearshore environments.
Origin of synergistic effects in bicomponent cobalt oxide-platinum catalysts for selective hydrogenation reaction
Authors: Zhang Jiankang , Gao Zhe , Wang Sen , Wang Guofu , Gao Xiaofeng , Zhang Baiyan , Xing Shuangfeng , Zhao Shichao , Qin Yong 
Published: September 2019

AbstractThe synergistic nature of bicomponent catalysts remains a challenging issue, due to the difficulty in constructing well-defined catalytic systems. Here we study the origin of synergistic effects in CoOx-Pt catalysts for selective hydrogenation by designing a series of closely contacted CoOxPt/TiO2 and spatially separated CoOx/TiO2/Pt catalysts by atomic layer deposition (ALD). For CoOx/TiO2/Pt, CoOx and platinum are separated by the walls of titania nanotubes, and the CoOx-Pt intimacy can be precisely tuned. Like CoOxPt/TiO2, the CoOx/TiO2/Pt shows higher selectivity to cinnamyl alcohol than monometallic TiO2/Pt, indicating that the CoOx-Pt nanoscale intimacy almost has no influence on the selectivity. The enhanced selectivity is ascribed to the increased oxygen vacancy resulting from the promoted hydrogen spillover. Moreover, platinum-oxygen vacancy interfacial sites are identified as the active sites by selectively covering CoOx or platinum by ALD. Our study provides a guide for the understanding of synergistic nature in bicomponent and bifunctional catalysts.
Gaussian synapses for probabilistic neural networks
Authors: Sebastian Amritanand , Pannone Andrew , Subbulakshmi Radhakrishnan Shiva , Das Saptarshi 
Published: September 2019

AbstractThe recent decline in energy, size and complexity scaling of traditional von Neumann architecture has resurrected considerable interest in brain-inspired computing. Artificial neural networks (ANNs) based on emerging devices, such as memristors, achieve brain-like computing but lack energy-efficiency. Furthermore, slow learning, incremental adaptation, and false convergence are unresolved challenges for ANNs. In this article we, therefore, introduce Gaussian synapses based on heterostructures of atomically thin two-dimensional (2D) layered materials, namely molybdenum disulfide and black phosphorus field effect transistors (FETs), as a class of analog and probabilistic computational primitives for hardware implementation of statistical neural networks. We also demonstrate complete tunability of amplitude, mean and standard deviation of the Gaussian synapse via threshold engineering in dual gated molybdenum disulfide and black phosphorus FETs. Finally, we show simulation results for classification of brainwaves using Gaussian synapse based probabilistic neural networks.
The distinction of CPR bacteria from other bacteria based on protein family content
Authors: Méheust Raphaël , Burstein David , Castelle Cindy J. , Banfield Jillian F. 
Published: September 2019

AbstractCandidate phyla radiation (CPR) bacteria separate phylogenetically from other bacteria, but the organismal distribution of their protein families remains unclear. Here, we leveraged sequences from thousands of uncultivated organisms and identified protein families that co-occur in genomes, thus are likely foundational for lineage capacities. Protein family presence/absence patterns cluster CPR bacteria together, and away from all other bacteria and archaea, partly due to proteins without recognizable homology to proteins in other bacteria. Some are likely involved in cell-cell interactions and potentially important for episymbiotic lifestyles. The diversity of protein family combinations in CPR may exceed that of all other bacteria. Over the bacterial tree, protein family presence/absence patterns broadly recapitulate phylogenetic structure, suggesting persistence of core sets of proteins since lineage divergence. The CPR could have arisen in an episode of dramatic but heterogeneous genome reduction or from a protogenote community and co-evolved with other bacteria.
A ribose-functionalized NAD+ with unexpected high activity and selectivity for protein poly-ADP-ribosylation
Authors: Zhang Xiao-Nan , Cheng Qinqin , Chen Jingwen , Lam Albert T. , Lu Yanran , Dai Zhefu , Pei Hua , Evdokimov Nikolai M. , Louie Stan G. , Zhang Yong 
Published: September 2019

AbstractNicotinamide adenine dinucleotide (NAD+)-dependent ADP-ribosylation plays important roles in physiology and pathophysiology. It has been challenging to study this key type of enzymatic post-translational modification in particular for protein poly-ADP-ribosylation (PARylation). Here we explore chemical and chemoenzymatic synthesis of NAD+ analogues with ribose functionalized by terminal alkyne and azido groups. Our results demonstrate that azido substitution at 3′-OH of nicotinamide riboside enables enzymatic synthesis of an NAD+ analogue with high efficiency and yields. Notably, the generated 3′-azido NAD+ exhibits unexpected high activity and specificity for protein PARylation catalyzed by human poly-ADP-ribose polymerase 1 (PARP1) and PARP2. And its derived poly-ADP-ribose polymers show increased resistance to human poly(ADP-ribose) glycohydrolase-mediated degradation. These unique properties lead to enhanced labeling of protein PARylation by 3′-azido NAD+ in the cellular contexts and facilitate direct visualization and labeling of mitochondrial protein PARylation. The 3′-azido NAD+ provides an important tool for studying cellular PARylation.
All optical dynamic nanomanipulation with active colloidal tweezers
Authors: Ghosh Souvik , Ghosh Ambarish 
Published: September 2019

AbstractManipulation of colloidal objects with light is important in diverse fields. While performance of traditional optical tweezers is restricted by the diffraction-limit, recent approaches based on plasmonic tweezers allow higher trapping efficiency at lower optical powers but suffer from the disadvantage that plasmonic nanostructures are fixed in space, which limits the speed and versatility of the trapping process. As we show here, plasmonic nanodisks fabricated over dielectric microrods provide a promising approach toward optical nanomanipulation: these hybrid structures can be maneuvered by conventional optical tweezers and simultaneously generate strongly confined optical near-fields in their vicinity, functioning as near-field traps themselves for colloids as small as 40 nm. The colloidal tweezers can be used to transport nanoscale cargo even in ionic solutions at optical intensities lower than the damage threshold of living micro-organisms, and in addition, allow parallel and independently controlled manipulation of different types of colloids, including fluorescent nanodiamonds and magnetic nanoparticles.