bluuebunny/crossref_metadata_2025 huggingface dataset:
Paleoaltimetry Potentiality of Branched GDGTs From Southern Tibet
Authors: Bai Yan , Chen Chihao , Xu Qiang , Fang Xiaomin
Published: February 2018

Paleoaltimetric reconstructions of the southern Tibetan Plateau (TP) are crucial to understand the processes and mechanisms concomitant with the tectonic collision of the Indian and Eurasian continental plates. We measured the branched glycerol dialkyl glycerol tetraether (brGDGT) indices from 88 surface soils from the southern TP and found that alkaline soils exhibited lower MBT′ and MBT′/CBT‐derived MAT (mean annual temperature), while MBT′/CBT‐derived MAT exhibited a strong correlation with altitude (R2 = 0.84; n = 63) for all of the localities with neutral and acidic soils. Differently, we found that MBT′5ME‐derived MAT exhibited a strong relation with altitude even though a mixture of alkaline samples (R2 = 0.72; n = 83). As a result, two regional calibrations were developed, including a neutral and acidic soil calibration based on MBT′/CBT‐MAT and a calibration suitable for both acidic and alkaline soils based on MBT′5ME‐MAT for the southern TP. Based on this new soil calibration data set, and a recent global soil calibration data set founded on MBT′5ME, we calculated paleo‐MAT of ∼9.49 ± 1.15 to 10.38 ± 1.47°C at ∼15 Ma, respectively, for the Namling Basin. Applying these soil calibrations, the paleoaltitudes of the Namling Basin can be calculated to have been between 4.36 ± 0.41 km above sea level (asl) and 4.43 ± 0.36 km asl at ∼15 Ma, respectively, similar to the paleoaltitudes of ∼4.7–5.4 km asl at ∼15 Ma inferred from the floral physiognomy of Namling Basin fossils and stable isotopes. These findings would suggest the applicability of MBT′/CBT (and/or MBT′5ME) indices as paleotopographic and paleotemperature proxies on the southern TP.
30 Years in the Life of an Active Submarine Volcano: A Time‐Lapse Bathymetry Study of the Kick‐'em‐Jenny Volcano, Lesser Antilles
Authors: Allen R. W. , Berry C. , Henstock T. J. , Collier J. S. , Dondin F. J‐Y. , Rietbrock A. , Latchman J. L. , Robertson R. E. A.
Published: February 2018

Effective monitoring is an essential part of identifying and mitigating volcanic hazards. In the submarine environment this is more difficult than onshore because observations are typically limited to land‐based seismic networks and infrequent shipboard surveys. Since the first recorded eruption in 1939, the Kick‐'em‐Jenny (KeJ) volcano, located 8 km off northern Grenada, has been the source of 13 episodes of T‐phase signals. These distinctive seismic signals, often coincident with heightened body‐wave seismicity, are interpreted as extrusive eruptions. They have occurred with a recurrence interval of around a decade, yet direct confirmation of volcanism has been rare. By conducting new bathymetric surveys in 2016 and 2017 and reprocessing 4 legacy data sets spanning 30 years we present a clearer picture of the development of KeJ through time. Processed grids with a cell size of 5 m and vertical precision on the order of 1–4 m allow us to correlate T‐phase episodes with morphological changes at the volcano's edifice. In the time‐period of observation 7.09 × 106m3of material has been added through constructive volcanism – yet 5 times this amount has been lost through landslides. Limited recent magma production suggests that KeJ may be susceptible to larger eruptions with longer repeat times than have occurred during the study interval, behavior more similar to sub‐aerial volcanism in the arc than previously thought. T‐phase signals at KeJ have a varied origin and are unlikely to be solely the result of extrusive submarine eruptions. Our results confirm the value of repeat swath bathymetry surveys in assessing submarine volcanic hazards.
Storm Time Evolution of Outer Radiation Belt Relativistic Electrons by a Nearly Continuous Distribution of Chorus
Authors: Yang Chang , Xiao Fuliang , He Yihua , Liu Si , Zhou Qinghua , Guo Mingyue , Zhao Wanli
Published: February 2018

During the 13–14 November 2012 storm, Van Allen Probe A simultaneously observed a 10 h period of enhanced chorus (including quasi‐parallel and oblique propagation components) and relativistic electron fluxes over a broad range of L = 3–6 and magnetic local time = 2–10 within a complete orbit cycle. By adopting a Gaussian fit to the observed wave spectra, we obtain the wave parameters and calculate the bounce‐averaged diffusion coefficients. We solve the Fokker‐Planck diffusion equation to simulate flux evolutions of relativistic (1.8–4.2 MeV) electrons during two intervals when Probe A passed the location L = 4.3 along its orbit. The simulating results show that chorus with combined quasi‐parallel and oblique components can produce a more pronounced flux enhancement in the pitch angle range ∼45°–80°, consistent well with the observation. The current results provide the first evidence on how relativistic electron fluxes vary under the drive of almost continuously distributed chorus with both quasi‐parallel and oblique components within a complete orbit of Van Allen Probe.
A Model of Aftershock Migration Driven by Afterslip
Authors: Perfettini H. , Frank W. B. , Marsan D. , Bouchon M.
Published: February 2018

Aftershocks region have been extensively reported to expand logarithmically with time. The associated migration velocity is typically of the order of several km/decade but can be much larger, especially when observing early aftershock sequences, seismic swarms, or tremors. We present here a model for the expansion of aftershock zones based on the idea that aftershocks are triggered as afterslip grows with time along the fault. One of the model assumptions is that aftershocks are triggered when a critical level of afterslip is reached. We predict that the migration velocity Vp at time t following the mainshock is given by
, where
is a frictional parameter, Δτ a characteristic value for the stress perturbation, c the radius of the stress perturbation, and ζ a constant of order unity. The scaling
implies a logarithmic expansion of the aftershock zone with time. The migration velocities predicted by our model are in quantitative agreement with the observations reported following aftershock sequence of small and large earthquakes in various tectonic settings, seismic swarms, and tremor sequences.
Multidecadal Variability in Surface Albedo Feedback Across CMIP5 Models
Authors: Schneider Adam , Flanner Mark , Perket Justin
Published: February 2018

Previous studies quantify surface albedo feedback (SAF) in climate change, but few assess its variability on decadal time scales. Using the Coupled Model Intercomparison Project Version 5 (CMIP5) multimodel ensemble data set, we calculate time evolving SAF in multiple decades from surface albedo and temperature linear regressions. Results are meaningful when temperature change exceeds 0.5 K. Decadal‐scale SAF is strongly correlated with century‐scale SAF during the 21st century. Throughout the 21st century, multimodel ensemble mean SAF increases from 0.37 to 0.42 W m−2 K−1. These results suggest that models' mean decadal‐scale SAFs are good estimates of their century‐scale SAFs if there is at least 0.5 K temperature change. Persistent SAF into the late 21st century indicates ongoing capacity for Arctic albedo decline despite there being less sea ice. If the CMIP5 multimodel ensemble results are representative of the Earth, we cannot expect decreasing Arctic sea ice extent to suppress SAF in the 21st century.
A Multipixel Time Series Analysis Method Accounting for Ground Motion, Atmospheric Noise, and Orbital Errors
Authors: Jolivet R. , Simons M.
Published: February 2018

Interferometric synthetic aperture radar time series methods aim to reconstruct time‐dependent ground displacements over large areas from sets of interferograms in order to detect transient, periodic, or small‐amplitude deformation. Because of computational limitations, most existing methods consider each pixel independently, ignoring important spatial covariances between observations. We describe a framework to reconstruct time series of ground deformation while considering all pixels simultaneously, allowing us to account for spatial covariances, imprecise orbits, and residual atmospheric perturbations. We describe spatial covariances by an exponential decay function dependent of pixel‐to‐pixel distance. We approximate the impact of imprecise orbit information and residual long‐wavelength atmosphere as a low‐order polynomial function. Tests on synthetic data illustrate the importance of incorporating full covariances between pixels in order to avoid biased parameter reconstruction. An example of application to the northern Chilean subduction zone highlights the potential of this method.
Evidence for the Maintenance of Slowly Varying Equatorial Currents by Intraseasonal Variability
Authors: Greatbatch Richard J. , Claus Martin , Brandt Peter , Matthießen Jan‐Dirk , Tuchen Franz Philip , Ascani François , Dengler Marcus , Toole John , Roth Christina , Farrar J. Thomas
Published: February 2018

Recent evidence from mooring data in the equatorial Atlantic reveals that semiannual and longer time scale ocean current variability is close to being resonant with equatorial basin modes. Here we show that intraseasonal variability, with time scales of tens of days, provides the energy to maintain these resonant basin modes against dissipation. The mechanism is analogous to that by which storm systems in the atmosphere act to maintain the atmospheric jet stream. We demonstrate the mechanism using an idealized model setup that exhibits equatorial deep jets. The results are supported by direct analysis of available mooring data from the equatorial Atlantic Ocean covering a depth range of several thousand meters. The analysis of the mooring data suggests that the same mechanism also helps maintain the seasonal variability.
Decadal Monsoon‐ENSO Relationships Reexamined
Authors: Yun Kyung‐Sook , Timmermann Axel
Published: February 2018

The strength of the El Niño‐Southern Oscillation (ENSO)‐Indian summer monsoon rainfall (ISMR) relationship shows considerable decadal fluctuations, which have been previously linked to low‐frequency climatic processes such as shifts in ENSO's center of action or the Atlantic Multidecadal Oscillation. However, random variability can also cause similar variations in the relationship between climate phenomena. Here we propose a statistical test to determine whether the observed time‐evolving correlations between ENSO and ISMR are different from those expected from a simple stochastic null hypothesis model. The analysis focuses on the time evolution of moving correlations, their expected variance, and probabilities for rapid transitions. The results indicate that the time evolution of the observed running correlation between these climate modes is indistinguishable from a system in which the ISMR signal can be expressed as a stochastically perturbed ENSO signal. This challenges previous deterministic interpretations. Our results are further corroborated by the analysis of climate model simulations.
Radiation Measured for Chinese Satellite SJ‐10 Space Mission
Authors: Zhou Dazhuang , Sun Yeqing , Zhang Binquan , Zhang Shenyi , Sun Yueqiang , Liang Jinbao , Zhu Guangwu , Jing Tao , Yuan Bin , Zhang Huanxin , Zhang Meng , Wang Wei , Zhao Lei
Published: February 2018

Abstracts

Space biological effects are mainly a result of space radiation particles with high linear energy transfer (LET); therefore, accurate measurement of high LET space radiation is vital. The radiation in low Earth orbits is composed mainly of high‐energy galactic cosmic rays (GCRs), solar energetic particles, particles of radiation belts, the South Atlantic Anomaly, and the albedo neutrons and protons scattered from the Earth's atmosphere. CR‐39 plastic nuclear track detectors sensitive to high LET are the best passive detectors to measure space radiation. The LET method that employs CR‐39 can measure all the radiation LET spectra and quantities. CR‐39 detectors can also record the incident directions and coordinates of GCR heavy ions that pass through both CR‐39 and biosamples, and the impact parameter, the distance between the particle's incident point and the seed's spore, can then be determined. The radiation characteristics and impact parameter of GCR heavy ions are especially beneficial for in‐depth research regarding space radiation biological effects. The payload returnable satellite SJ‐10 provided an excellent opportunity to investigate space radiation biological effects with CR‐39 detectors. The space bio‐effects experiment was successfully conducted on board the SJ‐10 satellite. This paper introduces space radiation in low Earth orbits and the LET method in radiation‐related research and presents the results of nuclear tracks and biosamples hitting distributions of GCR heavy ions, the radiation LET spectra, and the quantities measured for the SJ‐10 space mission. The SJ‐10 bio‐experiment indicated that radiation may produce significant bio‐effects.
Seismicity Controlled by a Frictional Afterslip During a Small‐Magnitude Seismic Sequence (ML < 5) on the Chihshang Fault, Taiwan
Authors: Canitano Alexandre , Godano Maxime , Hsu Ya‐Ju , Lee Hsin‐Ming , Linde Alan T. , Sacks Selwyn
Published: February 2018

We report evidence for frictional afterslip at shallow depths (about 5 to 7 km) during a small‐magnitude seismic sequence (withML<5) along the Chihshang Fault, a main active structure of the Longitudinal Valley, in southeast Taiwan. The afterslip, which was recorded by a nearby borehole dilatometer, lasted about a month with a cumulative geodetic moment magnitude of 4.8 ± 0.2. The afterslip comprised two stages and controlled the aftershock sequence. The first postseismic stage, which followed aML4.6 earthquake, lasted about 6 h and mostly controlled the ruptures of neighboring asperities (e.g., multiplets) near the hypocenter. Then, a 4 week duration large afterslip event following aML4.9 earthquake controlled the rate of aftershocks during its first 2 days through brittle creep. The study presents a rare case of simultaneous seismological and geodetic observations for afterslip following earthquakes with magnitude lower than 5. Furthermore, the geodetic moment of the postseismic phase is at least equivalent to the coseismic moment of the sequence.
The Role of Oceanic Transform Faults in Seafloor Spreading: A Global Perspective From Seismic Anisotropy
Authors: Eakin Caroline M. , Rychert Catherine A. , Harmon Nicholas
Published: February 2018

Mantle anisotropy beneath mid‐ocean ridges and oceanic transforms is key to our understanding of seafloor spreading and underlying dynamics of divergent plate boundaries. Observations are sparse, however, given the remoteness of the oceans and the difficulties of seismic instrumentation. To overcome this, we utilize the global distribution of seismicity along transform faults to measure shear wave splitting of over 550 direct S phases recorded at 56 carefully selected seismic stations worldwide. Applying this source‐side splitting technique allows for characterization of the upper mantle seismic anisotropy, and therefore the pattern of mantle flow, directly beneath seismically active transform faults. The majority of the results (60%) return nulls (no splitting), while the non‐null measurements display clear azimuthal dependency. This is best simply explained by anisotropy with a near vertical symmetry axis, consistent with mantle upwelling beneath oceanic transforms as suggested by numerical models. It appears therefore that the long‐term stability of seafloor spreading may be associated with widespread mantle upwelling beneath the transforms creating warm and weak faults that localize strain to the plate boundary.
New Results on Ionospheric Irregularity Drift Velocity Estimation Using Multi‐GNSS Spaced‐Receiver Array During High‐Latitude Phase Scintillation
Authors: Wang Jun , Morton Y. Jade , Hampton Donald
Published: February 2018

The spaced‐receiver technique using Global Navigation Satellite Systems (GNSS) receivers offers an inexpensive approach for estimating ionospheric irregularity velocity during ionospheric scintillations. Our previous work has demonstrated that correlative studies of the GNSS carrier phase variations can be used to derive irregularity drift velocity at high latitudes. This study expanded upon our previous projects by incorporating Global Navigation Satellite System (GLONASS) signals, investigation on ionospheric irregularity height assumption, and all‐sky imager measurements into the methodology. A case study is presented based on Global Positioning System, Galileo, and GLONASS measurements during a geomagnetic storm event on 20 December 2015, obtained from a closely spaced receiver array at Poker Flat Research Range near Fairbanks, Alaska. The GNSS‐estimated irregularity drift velocities are in general agreement with the measurements from the Poker Flat Incoherent Scatter Radar and the Poker Flat all‐sky imager. The study also shows that the irregularity altitude assumption will not lead to significant variations in the irregularity drift velocity estimates, especially for satellites with relatively high elevations. The techniques presented in this paper demonstrate that GNSS receiver arrays can be used as powerful means to monitor the ionospheric plasma dynamics during space weather events.
Estimating the Natural Flow Regime of Rivers With Long‐Standing Development: The Northern Branch of the Rio Grande
Authors: Blythe Todd L. , Schmidt John C.
Published: February 2018

An estimate of a river's natural flow regime is useful for water resource planning and ecosystem rehabilitation by providing insight into the predisturbance form and function of a river. The natural flow regime of most rivers has been perturbed by development during the 20th century and in some cases, before stream gaging began. The temporal resolution of natural flows estimated using traditional methods is typically not sufficient to evaluate cues that drive native ecosystem function. Additionally, these traditional methods are watershed specific and require large amounts of data to produce accurate results. We present a mass balance method that estimates natural flows at daily time step resolution for the northern branch of the Rio Grande, upstream from the Rio Conchos, that relies only on easily obtained streamflow data. Using an analytical change point method, we identified periods of the measured flow regime during the 20th century for comparison with the estimated natural flows. Our results highlight the significant deviation from natural conditions that occurred during the 20th century. The total annual flow of the northern branch is 95% lower than it would be in the absence of human use. The current 2 year flood has decreased by more than 60%, is shorter in duration, and peaks later in the year. When compared to unregulated flows estimated using traditional mass balance accounting methods, our approach provides similar results.
Improved Characterization of Groundwater Flow in Heterogeneous Aquifers Using Granular Polyacrylamide (PAM) Gel as Temporary Grout
Authors: Klepikova Maria V. , Roques Clement , Loew Simon , Selker John
Published: February 2018

The range of options for investigation of hydraulic behavior of aquifers from boreholes has been limited to rigid, cumbersome packers, and inflatable sleeves. Here we show how a new temporary borehole sealing technique using soft grains of polyacrylamide (PAM) gel as a sealing material can be used to investigate natural groundwater flow dynamics and discuss other possible applications of the technology. If no compressive stress is applied, the gel packing, with a permeability similar to open gravel, suppresses free convection, allowing for local temperature measurements and chemical sampling through free‐flowing gel packing. Active heating laboratory and field experiments combined with temperature measurements along fiber optic cables were conducted in water‐filled boreholes and boreholes filled with soft grains of polyacrylamide gel. The gel packing is shown to minimize the effect of free convection within the well column and enable detection of thin zones of relatively high or low velocity in a highly transmissive alluvial aquifer, thus providing a significant improvement compared to temperature measurements in open boreholes. Laboratory experiments demonstrate that under modest compressive stress to the gel media the permeability transitions from highly permeable to nearly impermeable grouting. Under this configuration the gel packing could potentially allow for monitoring local response pressure from the formation with all other locations in the borehole hydraulically isolated.
Data‐Driven Model Uncertainty Estimation in Hydrologic Data Assimilation
Authors: Pathiraja S. , Moradkhani H. , Marshall L. , Sharma A. , Geenens G.
Published: February 2018

The increasing availability of earth observations necessitates mathematical methods to optimally combine such data with hydrologic models. Several algorithms exist for such purposes, under the umbrella of data assimilation (DA). However, DA methods are often applied in a suboptimal fashion for complex real‐world problems, due largely to several practical implementation issues. One such issue is error characterization, which is known to be critical for a successful assimilation. Mischaracterized errors lead to suboptimal forecasts, and in the worst case, to degraded estimates even compared to the no assimilation case. Model uncertainty characterization has received little attention relative to other aspects of DA science. Traditional methods rely on subjective, ad hoc tuning factors or parametric distribution assumptions that may not always be applicable. We propose a novel data‐driven approach (named SDMU) to model uncertainty characterization for DA studies where (1) the system states are partially observed and (2) minimal prior knowledge of the model error processes is available, except that the errors display state dependence. It includes an approach for estimating the uncertainty in hidden model states, with the end goal of improving predictions of observed variables. The SDMU is therefore suited to DA studies where the observed variables are of primary interest. Its efficacy is demonstrated through a synthetic case study with low‐dimensional chaotic dynamics and a real hydrologic experiment for one‐day‐ahead streamflow forecasting. In both experiments, the proposed method leads to substantial improvements in the hidden states and observed system outputs over a standard method involving perturbation with Gaussian noise.
Agreement, Modeling of Categorical
Authors: Nelson Kerrie P. , Barlow William
Published: February 2018

This article describes models and summary measures that can be used for assessing the agreement between raters' categorical classifications. Models often describe the agreement between observers in ways that are more satisfactory than using simple single measures such as kappa. These models take chance agreement and ordinal association into account, and the effects of covariates may also be incorporated. Modeling techniques include logistic regression models, the log‐linear model, generalized linear mixed models, and models using generalized estimating equations when more than two categories are involved. More complex models are required if there are more than two raters.
Agent‐Based Modeling
Authors: Grow André , Van Bavel Jan
Published: February 2018

This article discusses how agent‐based modeling can be used to study complex and dynamic social systems consisting of heterogeneous and interdependent actors. It reviews central aspects of developing agent‐based models, provides an overview of common methodological issues, and compares the method with other approaches to the study of social systems.
Quality Assurance and Issues in Healthcare Quality
Authors: Mitra Amitava
Published: February 2018

The healthcare sector in the United States is rather unique. This is due to the various customers, their associated needs, multiple entities who pay for the services, and the different types of payment schemes. Beyond this lies the challenge of selecting appropriate metrics to monitor quality. In this article, we discuss the role of information technology in the healthcare sector, and the obstacles and challenges in its implementation to improve the quality of care and reduce costs. We examine one particular area of analyzing customer satisfaction data as this is a common form of data collection in the healthcare sector.
Semiparametric Theory
Authors: Kennedy Edward H.
Published: February 2018

In this article, we give a brief review of semiparametric theory, using as a running example the common problem of estimating an average causal effect. Semiparametric models allow at least part of the data‐generating process to be unspecified and unrestricted, and can often yield robust estimators that nonetheless behave similarly to those based on parametric likelihood assumptions, for example, fast rates of convergence to normal limiting distributions. We discuss the basics of semiparametric theory, focusing on influence functions.
StochasticEM
Authors: Nielsen Søren Feodor
Published: February 2018

The expectation maximization (EM) algorithm is a useful tool for finding the maximum likelihood estimator (MLE) in incomplete data problems. In some problems, however, the E step (and/or the M step) of the algorithm may be difficult to implement. Here, the stochastic EM algorithm can provide a useful alternative by replacing the E step of the EM algorithm with a fixed number of simulations, turning the M step into a maximization of the complete data log‐likelihood. The output of the stochastic EM algorithm forms a Markov chain that under sufficient regularity conditions is ergodic with an asymptotically normal invariant distribution. Draws from the invariant distribution form a consistent asymptotically normal estimator of the unknown parameters.
Ordering and Grain Growth in Charged Block Copolymer Bulk Films: A Comparison of Solvent‐Related Processes
Authors: Ryan Justin J. , Mineart Kenneth P. , Lee Byeongdu , Spontak Richard J.
Published: February 2018

While prior efforts have demonstrated that the morphologies of block copolymer (BC) bulk films can be controlled through judicious chemical design and thermal annealing, recent interest has focused on regulating the orientation of BC nanostructures and minimizing defects. Thermal processes developed to achieve this purpose for nonpolar BCs are not, however, suitable for orienting microphase‐ordered BCs composed of at least one block with charged moieties that can form thermally stable ionic clusters. To overcome this challenge, we have previously applied solvent‐vapor (SV) annealing to block ionomer (BI) bulk films composed of midblock‐sulfonated pentablock copolymers and established that this approach yields highly ordered morphologies that display evidence of improved in‐plane orientation. Here, we employ small‐angle X‐ray scattering to compare the effectiveness of three solvent‐related processes–SV annealing, SV permeation, and SV sorption–on BI ordering and grain growth, and offer explanations for observed differences on the basis of thermodynamic‐ and transport‐related considerations. Differences in the experimental design of these solvent‐related processes are found to affect nanostructural development, as evidenced by the extent of in‐plane grain growth.
A Tunable Multigate Indium‐Tin‐Oxide‐Assisted All‐Dielectric Metasurface
Authors: Forouzmand Ali , Salary Mohammad Mahdi , Inampudi Sandeep , Mosallaei Hossein
Published: February 2018

In this paper, an optically active reflective metasurface with tunable phase performance is designed which operates based on the excitation of both electric and magnetic resonances in a silicon‐made nanoantenna element and the use of layered indium tin oxide (ITO)–alumina under the influence of external multigate biasing. The capability of achieving robust control over the reflection characteristics of two closely spaced electric and magnetic resonances is investigated. Adopting the multigate biasing enables relatively high reflection amplitude of 0.4 over the entire phase‐change coverage (≈180°) in the near‐infrared regime by exploiting the constructive interference between the geometrical resonances. The physical mechanism behind this ITO‐assisted metal–insulator–semiconductor building block can be described as the strong confinement of electromagnetic fields at the vicinity of ITO layers and the possibility of modulating the carrier concentrations of the integrated active materials by electrically varying the bias voltage. The uniformity of reflection magnitude for all reflection phase coverage, relatively high reflectivity, and electro‐optical tunability is leveraged to design three multifunctional devices with step‐by‐step increase in complexity of biasing network including ultrathin reconfigurable linear/circular polarizer (simple identical biasing), dynamical beam steering platform (two‐state biasing), and tunable metalens with controllable on‐ and off‐axes focusing pattern in real‐time (advanced element‐by‐element biasing).
Regulating Secondary Flow in Ultra‐Low Aspect Ratio Microchannels by Dimensional Confinement
Authors: Shen Shaofei , Kou Lisha , Zhang Xuan , Wang Defu , Niu Yanbing , Wang Jinyi
Published: February 2018

The ability to control the movement of fluids is significant in biological analysis, chemical synthesis, and medical diagnostics. Microfluidic technologies have achieved promising progresses in fluid manipulation by curvilinear channel geometries due to the presence of secondary flows. However, most of these devices are not designed in low aspect ratio microchannels because of the difficulty of weak Dean effect. Herein, we describe an inertial microfluidic system that allows deterministic regulation of secondary flows by geometric confinement in ultra‐low aspect ratio microchannels. On the introduction of a series of micro‐obstacles in semicircular microchannels, the resulting acceleration of secondary flow can be applied to remarkably potentiate many molecular interactions and reactions with a high mixing efficiency and speed under a wide range of flow capacity. The strategy to engineer secondary flow used in this work offers new insights pointing to low aspect ratio, ease‐to‐use, high‐throughput, and considerable flexibility for designing efficient microfluidic devices in diverse fluid manipulations.
International investigation of neurocognitive and behavioral phenotype in 47,XXY (Klinefelter syndrome): Predicting individual differences
Authors: Samango‐Sprouse Carole , Stapleton Emily , Chea Selena , Lawson Patrick , Sadeghin Teresa , Cappello Chris , de Sonneville Leo , van Rijn Sophie
Published: February 2018

47,XXY (KS) occurs in 1:650 male births, though less than 25% are ever identified. We assessed stability of neurocognitive features across diverse populations and quantified factors mediating outcome. Forty‐four boys from the Netherlands (NL) and 54 boys from the United States (US) participated. The Wechsler Intelligence Scales assessed intellectual functioning; the ANT program evaluated cognitive function; and the CBCL assessed behavioral functioning. ANOVA was used for group comparisons. Hierarchical regressions assessed variance explained by each independent variable: parental education, timing of diagnosis, testosterone, age, and nationality. Parental education, timing of diagnosis, and hormonal treatment all played an important role in neurocognitive performance. The observed higher IQ and better attention regulation in the US group as compared to the NL group was observed with decreased levels of behavioral problems in the US group. Cognitive measures that were different between the NL and US groups, i.e., attention regulation and IQ scores, were also significantly influenced by external factors including timing of diagnosis, testosterone treatment, and parental education. On the ANT, a cognitive phenotype of 47,XXY was observed, with similar scores on 9 out of the 10 ANT subtests for the NL and US groups. This study lays additional features to the foundation for an algorithm linking external variables to outcome on various neurodevelopmental measures.
Microsatellite markers for study of the invasive species Rumex alpinus (Polygonaceae)
Authors: Šurinová Mária , Jarošová Andrea , Münzbergová Zuzana
Published: February 2018

Premise of the Study

Polymorphic microsatellite markers were developed to study genetic diversity, population structure, and dispersal strategies of the highly invasive species Rumex alpinus (Polygonaceae).

Methods and Results

Fifteen polymorphic microsatellite loci were developed using a 454 sequencing approach and used to genotype 72 individuals from six populations in Austria and France. All markers were polymorphic in at least one investigated population, and the number of alleles ranged from one to four alleles per locus. Observed and expected heterozygosity ranged from 0.06 to 1.0 and from 0.18 to 0.72, respectively.

Conclusions

These 15 markers will be useful for characterizing dispersal strategies and gene flow assessment between R. alpinus populations and other, often weedy Rumex species.
Reversal of Sepsis‐Like Features of Neutrophils by Interleukin‐1 Blockade in Patients With Systemic‐Onset Juvenile Idiopathic Arthritis
Authors: ter Haar Nienke M. , Tak Tamar , Mokry Michal , Scholman Rianne C. , Meerding Jenny M. , de Jager Wilco , Verwoerd Anouk , Foell Dirk , Vogl Thomas , Roth Johannes , Leliefeld Pieter H. C. , van Loosdregt Jorg , Koenderman Leo , Vastert Sebastiaan J. , de Roock Sytze
Published: February 2018

Objective

Neutrophils are the most abundant innate immune cells in the blood, but little is known about their role in (acquired) chronic autoinflammatory diseases. This study was undertaken to investigate the role of neutrophils in systemic‐onset juvenile idiopathic arthritis (JIA), a prototypical multifactorial autoinflammatory disease that is characterized by arthritis and severe systemic inflammation.

Methods

Fifty patients with systemic‐onset JIA who were receiving treatment with recombinant interleukin‐1 receptor antagonist (rIL‐1Ra; anakinra) were analyzed at disease onset and during remission. RNA sequencing was performed on fluorescence‐activated cell–sorted neutrophils from 3 patients with active systemic‐onset JIA and 3 healthy controls. Expression of activation markers, apoptosis, production of reactive oxygen species (ROS), and degranulation of secretory vesicles from neutrophils were assessed by flow cytometry in serum samples from 17 patients with systemic‐onset JIA and 15 healthy controls.

Results

Neutrophil counts were markedly increased at disease onset, and this correlated with the levels of inflammatory mediators. The neutrophil counts normalized within days after the initiation of rIL‐1Ra therapy. RNA‐sequencing analysis revealed a substantial up‐regulation of inflammatory processes in neutrophils from patients with active systemic‐onset JIA, significantly overlapping with the transcriptome of sepsis. Correspondingly, neutrophils from patients with active systemic‐onset JIA displayed a primed phenotype that was characterized by increased ROS production, CD62L shedding, and secretory vesicle degranulation, which was reversed by rIL‐1Ra treatment in patients who had achieved clinical remission. Patients with a short disease duration had high neutrophil counts, more immature neutrophils, and a complete response to rIL‐1Ra, whereas patients with symptoms for >1 month had normal neutrophil counts and an unsatisfactory response to rIL‐1Ra. In vitro, rIL‐1Ra antagonized the priming effect of IL‐1β on neutrophils from healthy subjects.

Conclusion

These results strongly support the notion that neutrophils play an important role in systemic‐onset JIA, especially in the early inflammatory phase of the disease. The findings also demonstrate that neutrophil numbers and the inflammatory activity of systemic‐onset JIA are both susceptible to IL‐1 blockade.
Influence of family demographic factors on social communication questionnaire scores
Authors: Rosenberg Steven A. , Moody Eric J. , Lee Li‐Ching , DiGuiseppi Carolyn , Windham Gayle C. , Wiggins Lisa D. , Schieve Laura A. , Ledbetter Caroline M. , Levy Susan E. , Blaskey Lisa , Young Lisa , Bernal Pilar , Rosenberg Cordelia R. , Fallin M. Daniele
Published: February 2018

This study examined the effect of demographic factors on Social Communication Questionnaire (SCQ) scores in children aged 30–68 months. Diagnoses of ASD were made after a gold standard evaluation that included the Autism Diagnostic Observation Schedule (ADOS), and the Autism Diagnostic Interview Revised (ADI‐R). The relationship of demographic variables to SCQ scores was compared in two source populations: (a) children recruited from clinical and educational sources serving children who have ASD or other developmental disorders (CE) and (b) children recruited from birth certificates to represent the general population (BC). The impact of the demographic variables—child sex, child age, maternal language, maternal ethnicity, maternal education, maternal race, and household income—on total SCQ score were studied to examine their impact on the SCQ's performance. Demographic factors predicting the SCQ total score were used to generate ROCs. Factors that had a significant influence on SCQ performance were identified by examining the area under the ROCs. Optimal SCQ cut‐points were generated for significant factors using the Youden's Index. Overall male sex, lower household income, lower maternal education and Black race predicted higher SCQ scores. In this sample, the most common optimum value for the SCQ cut‐point across the different sociodemographic groups was 11. Autism Res 2018, 11: 695–706. © 2018 International Society for Autism Research, Wiley Periodicals, Inc.

Lay Summary

Screeners are used to help identify children who are more likely to have ASD than their peers. Ideally screeners should be accurate for different groups of children and families. This study examined how well the Social Communication Questionnaire (SCQ) predicts ASD. We found that male sex, lower household income, lower maternal education and Black race were associated with higher SCQ scores. In this study an SCQ cut‐point of 11 worked best across the different sociodemographic groups in our sample.
Optimierter Teilsicherheitsfaktor für Lasten aus Equipment im schweren Industriebau
Authors: Glowienka Simon
Published: February 2018

Die Berechnung von Baustrukturen im Industriebau erfolgt bislang auf Basis der baurechtlich eingeführten Regelwerke wie etwa DIN EN 1990 oder DIN EN 1992, um nur ein paar Beispiele zu nennen. Auf die entsprechenden Baustrukturen, wie z. B. Fundamente oder Bühnen, wirken neben den umweltbedingten Lasten vor allem auch Belastungen aus schwerem Equipment, die in der Regel auch maßgebend für die Bemessung werden. Da entsprechende Lasten vollständig, aber auch nur teilweise wirken können, gelten sie im Allgemeinen als veränderliche Lasten (Qk) im Sinne von DIN EN 1990 und werden daher üblicherweise mit dem Teilsicherheitsbeiwert γQ = 1,50 beaufschlagt, in besonderen Fällen darf γQ = 1,35 verwendet werden [1, 2]. Im Gegensatz zu sonstigen veränderlichen Einwirkungen verfügen Lasten aus Equipment jedoch nur über eine viel geringere Schwankungsbreite und sind generell genauer vorhersagbar. Daher verfügen Tragwerke, die basierend auf den eingeführten Normen bemessen sind, über ein deutlich höheres Zuverlässigkeitsniveau als nach DIN EN 1990 gefordert, was jedoch im Wiederspruch zu der Forderung steht, Tragwerke wirtschaftlich zu bemessen. Im Folgenden wird der Ansatz kritisch diskutiert und ein optimierter Vorschlag unterbreitet.
Thirty‐day readmission after spontaneous intracerebral hemorrhage
Authors: Bjerkreim Anna Therese , Khanevski Andrej Netland , Glad Solveig Bergliot , Thomassen Lars , Naess Halvor , Logallo Nicola
Published: February 2018

Background

Intracerebral hemorrhage (ICH) is the most severe form of stroke, but data on readmission after ICH are sparse. We aimed to determine frequency, causes, and predictors of 30‐day readmission after ICH.

Materials and Methods

This retrospective cohort study includes all spontaneous ICH survivors admitted to the stroke unit at Haukeland University Hospital in Bergen in Norway from July 2007 to December 2013. Patients were followed by review of electronic medical charts, and the first unplanned readmission within 30 days after discharge was used as final outcome. Cox regression analysis was performed to identify predictors of 30‐day readmission.

Results

We identified 226 patients with spontaneous ICH, 70 (31.0%) of whom died before discharge or were discharged to palliative care. Of the remaining 156 ICH survivors, 28 (18.0%) were readmitted within 30 days. Median time to readmission was 12 days (IQR 4.5 – 18.5). Most patients were readmitted due to infections (N = 13). None of the patients were readmitted with recurrent stroke. Pneumonia and enteral feeding during the index hospitalization were associated with readmission for infections (both p < .01). Age was the only independent predictor of readmission (HR 1.06, 95% CI 1.02 – 1.11, p = .006).

Conclusions

Almost one in five of our spontaneous ICH survivors was readmitted within 30 days, and most readmissions were caused by infections.
Data augmentation in food science: Synthesising spectroscopic data of vegetable oils for performance enhancement
Authors: Georgouli Konstantia , Osorio Maria Teresa , Martinez Del Rincon Jesus , Koidis Anastasios
Published: February 2018

Generating more accurate, efficient, and robust classification models in chemometrics, able to address real‐world problems in food analysis, is intrinsically related with the amount of available calibration samples. In this paper, we propose a data augmentation solution to increase the performance of a classification model by generating realistic data augmented samples. The feasibility of this solution has been evaluated on 3 main different experiments where Fourier transform mid infrared (FT‐IR) spectroscopic data of vegetable oils were used for the identification of vegetable oil species in oil admixtures. Results demonstrate that data augmented samples improved the classification rate by around 19% in a single instrument validation and provided a significant 38% improvement in classification when testing in more than 10 different spectroscopic instruments to the calibration one.
The impact of noninvasive follicular thyroid neoplasm with papillary‐like nuclear features on the rate of malignancy for atypia of undetermined significance subcategories
Authors: Hang Jen‐Fan , Westra William H. , Zhou Amy G. , Cooper David S. , Ali Syed Z.
Published: February 2018

BACKGROUND

The recent revision in terminology, with noninvasive follicular thyroid neoplasm with papillary‐like nuclear features (NIFTP) replacing noninvasive follicular variant of papillary thyroid carcinoma, has reclassified the clinically indolent tumor as nonmalignant. The objective of this study was to evaluate the impact of this change on the rate of malignancy (ROM) for subcategories of an atypia of undetermined significance (AUS) diagnosis on fine‐needle aspiration (FNA) cytology.

METHODS

Consecutive thyroid FNAs interpreted as AUS over a period of 4 years were retrospectively analyzed. The ROM for AUS subcategories, including atypia of undetermined significance with nuclear atypia (AUS‐N), atypia of undetermined significance with a microfollicular pattern (AUS‐F), atypia of undetermined significance with nuclear atypia and a microfollicular pattern (AUS‐N/F), atypia of undetermined significance with Hürthle cells (AUS‐H), and atypia of undetermined significance, not otherwise specified (AUS‐NOS), were analyzed.

RESULTS

Of the 426 nodules interpreted as AUS, 244 were surgically excised. The incidence of NIFTP in each subcategory was as follows: 18% for AUS‐N, 18% for AUS‐F, 9% for AUS‐N/F, 3% for AUS‐H, and 0% for AUS‐NOS. After the reclassification of NIFTP as nonmalignant, the ROM based on histologic follow‐up significantly decreased from 43% to 26% for AUS‐N (P < .001) and from 29% to 10% for AUS‐F (P = .008). The ROM for AUS‐N remained significantly higher than the ROM for AUS‐F (P = .030).

CONCLUSIONS

A subset of resected AUS nodules can be reclassified as NIFTP, and that significantly decreases the ROM, especially for AUS‐N and AUS‐F. Nonetheless, AUS‐N still harbors a substantially higher ROM than AUS‐F. Cancer Cytopathol 2018;126:309‐16. © 2018 American Cancer Society.
Statistical analysis on ambient RF energy harvesting for low‐power wireless applications
Authors: Inbaraj Divya , Kailasam Muthumeenakshi , Sankararajan Radha
Published: February 2018

Renewable energy sources from the earth constitute another option apart from the available ones for wellspring of energy for economizing on cost of power supply. The energy obtained from ambient sources is called energy harvesting. Energy‐harvesting low‐power systems have acquired a remarkable consideration as a viable hotspot for expanding both energy efficiency and spectral efficiency. Radio frequency (RF) energy harvesting from ambient source is a promising technique for fulfilling the irreplaceable power prerequisites for powering the low‐power devices. Hence, it requires the development of an antenna for harvesting RF energy. In this paper, a coplanar waveguide (CPW) antenna has been designed and fabricated using FR4 lossy substrate. This CPW antenna covers frequency bands from the most important RF patrons (GSM 900, GSM 1800, 3G, and Wi‐Fi) within the frequency range from (0.58 to 3 GHz) with a percentage fractional bandwidth of 116% with the center frequency of 1.65 GHz. The fabricated antenna then has been experimentally validated at SSN College of Engineering campus. The effects on the RF power density level for CPW antenna are examined by statistical approach known as Taguchi method. The L9 and L8 orthogonal arrays and analysis of variance are implemented to analyze the execution qualities. The CPW antenna control factors are distance, time, and number of receivers. Then, statistical test (P) are used to determine the significant factors on RF power density.
Prediction of designer drugs: Synthesis and spectroscopic analysis of synthetic cathinone analogs that may appear on the Swedish drug market
Authors: Carlsson Andreas , Sandgren Veronica , Svensson Stefan , Konradsson Peter , Dunne Simon , Josefsson Martin , Dahlén Johan
Published: February 2018

The use of hyphenated analytical techniques in forensic drug screening enables simultaneous identification of a wide range of different compounds. However, the appearance of drug seizures containing new substances, mainly new psychoactive substances (NPS), is steadily increasing. These new and other already known substances often possess structural similarities and consequently they exhibit spectral data with slight differences. This situation has made the criteria that ensure indubitable identification of compounds increasingly important. In this work, 6 new synthetic cathinones that have not yet appeared in any Swedish drug seizures were synthesized. Their chemical structures were similar to those of already known cathinone analogs of which 42 were also included in the study. Hence, a total of 48 synthetic cathinones making up sets of homologous and regioisomeric compounds were used to challenge the capabilities of various analytical techniques commonly applied in forensic drug screening, ie, gas chromatography–mass spectrometry (GC–MS), gas chromatography–Fourier transform infrared spectroscopy (GC–FTIR), nuclear magnetic resonance (NMR), and liquid chromatography quadrupole time‐of‐flight mass spectrometry (LC–QTOF–MS). Special attention was paid to the capabilities of GC–MS and GC–FTIR to distinguish between the synthetic cathinones and the results showed that neither GC–MS nor GC–FTIR alone can successfully differentiate between all synthetic cathinones. However, the 2 techniques proved to be complementary and their combined use is therefore beneficial. For example, the structural homologs were better differentiated by GC–MS, while GC–FTIR performed better for the regioisomers. Further, new spectroscopic data of the synthesized cathinone analogs is hereby presented for the forensic community. The synthetic work also showed that cathinone reference compounds can be produced in few reaction steps.