bluuebunny/crossref_metadata_2025 huggingface dataset:
Quasi-isotropic underwater acoustic carpet cloak based on latticed pentamode metafluid
Authors: Sun Zhaoyong , Sun Xuecong , Jia Han , Bi Yafeng , Yang Jun
Published: March 2019

We present a practical design of an underwater acoustic carpet cloak with 2-dimensional version of the pentamode lattice. The quasi-conformal transformation, which is achieved by inverse Laplace's equations with Neumann and Dirichlet boundaries, is used to obtain the required parameters of the impedance matching carpet cloak. The theoretical carpet cloak is pre-divided into 300 cells and then filled with the corresponding pentamode material unit cells to achieve the latticed pentamode carpet cloak. The simulation results indicate that the proposed carpet cloak has a good and broadband cloaking effect. Moreover, the technique in this work can also be used to design arbitrary shaped devices.
On the importance of anharmonicities and nuclear quantum effects in modelling the structural properties and thermal expansion of MOF-5
Authors: Lamaire Aran , Wieme Jelle , Rogge Sven M. J. , Waroquier Michel , Van Speybroeck Veronique
Published: March 2019

In this article, we investigate the influence of anharmonicities and nuclear quantum effects (NQEs) in modelling the structural properties and thermal expansion of the empty MOF-5 metal-organic framework. To introduce NQEs in classical molecular dynamics simulations, two different methodologies are considered, comparing the approximate, but computationally cheap, method of generalised Langevin equation thermostatting to the more advanced, computationally demanding path integral molecular dynamics technique. For both methodologies, similar results were obtained for all the properties under investigation. The structural properties of MOF-5, probed by means of radial distribution functions (RDFs), show some distinct differences with respect to a classical description. Besides a broadening of the RDF peaks under the influence of quantum fluctuations, a different temperature dependence is also observed due to a dominant zero-point energy (ZPE) contribution. For the thermal expansion of MOF-5, by contrast, NQEs appear to be only of secondary importance with respect to an adequate modelling of the anharmonicities of the potential energy surface (PES), as demonstrated by the use of two differently parametrised force fields. Despite the small effect in the temperature dependence of the volume of MOF-5, NQEs do however significantly affect the absolute volume of MOF-5, in which the ZPE resulting from the intertwining of NQEs and anharmonicities plays a crucial role. A sufficiently accurate description of the PES is therefore prerequisite when modelling NQEs.
Epistemic uncertainty quantification for Reynolds-averaged Navier-Stokes modeling of separated flows over streamlined surfaces
Authors: Gorlé C. , Zeoli S. , Emory M. , Larsson J. , Iaccarino G.
Published: March 2019

It is well known that linear eddy-viscosity turbulence models can introduce uncertainty in predictions for complex flow features such as separation and reattachment. The goal of this paper is to advance our understanding of a physics-based approach to quantify this turbulence model form uncertainty in Reynolds-averaged Navier-Stokes simulations of separated flows over streamlined surfaces. The methodology is based on perturbing the modeled Reynolds stresses in the momentum equations; perturbations are defined in terms of a decomposition of the Reynolds stress tensor, i.e., based on the tensor magnitude and the eigenvalues and eigenvectors of the normalized anisotropy tensor. We demonstrate that the accuracy of the predicted Reynolds stress magnitude is strongly influenced by the turbulence production term and subsequently explore the anisotropy tensor eigenvalue and eigenvector perturbations that maximize or minimize turbulence production; these could be expected to provide bounds on the prediction of separation and reattachment locations. The method uses two user-defined parameters to identify the spatial extent of the perturbed region and the magnitude of the eigenvalue perturbations. Results for the flow over a periodic wavy wall and over a three-dimensional hill indicate that the perturbations that increase turbulence production decrease the extent of the separation region, while perturbations that decrease production increase the region of separated flow. The predicted bounds can successfully encompass the reference data, provided the extent of the perturbed region and the eigenvalue perturbation magnitudes are sufficiently large. Importantly, we observed a monotonic behavior of the magnitude of the predicted bounds as a function of the two user-defined parameters.
The selenocyanate dimer radical anion in water: Transient Raman spectra, structure, and reaction dynamics
Authors: Janik Ireneusz , Tripathi G. N. R.
Published: March 2019

The selenocyanate dimer radical anion (SeCN)2•−, prepared by electron pulse irradiation of selenocyanate anion (SeCN)− in water, has been examined by transient absorption, time-resolved Raman spectra, and range-separated hybrid density functional (ωB97x and LC-ωPBE) theory. The Raman spectrum, excited in resonance with the 450 nm (λmax) absorption of the radical, is dominated by a very strong band at 140.5 cm−1, associated with the Se–Se stretching vibration, its overtones and combinations. A striking feature of the (SeCN)2•− Raman spectrum is the relative sharpness of the 140.5 cm−1 band compared to the S–S band at 220 cm−1 in thiocyanate radical anion (SCN)2•−, the difference of which is explained in terms of a time-averaged site effect. Calculations, which reproduce experimental frequencies fairly well, predict a molecular geometry with the SeSe bond length of 2.917 (±0.04) Å, the SeC bond length of 1.819 (±0.004) Å, and the CN bond length of 1.155 (±0.002) Å. An anharmonicity of 0.44 cm−1 has been determined for the 140.5 cm−1 Se–Se vibration which led to a dissociation energy of ∼1.4 eV for the SeSe bond, using the Morse potential in a diatomic approximation. This value, estimated for the radical confined in a solvent cage, compares well with the calculated gas-phase energy, 1.32 ± 0.04 eV, required for the radical to dissociate into (SeCN)• and (SeCN)− fragments. The enthalpy of dissociation in water has been measured (0.36 eV) and compared with the value estimated by accounting for the solvent dielectric effects in structural calculations.
Identifying the local defect structure in (Na0.5K0.5)NbO3: 1 mol. % CuO lead-free ceramics by x-ray absorption spectra
Authors: Fu Jian , Zuo Ruzhong , Qi He , Chan Tingshan
Published: March 2019

The local defect structure around dopant atoms in 1 mol. % CuO doped (Na0.5K0.5)NbO3 lead-free ceramics was investigated by means of x-ray absorption spectra as compared with the local structure around the host Nb site. The Cu K-edge and O K-edge x-ray absorption near-edge structure spectra demonstrate divalent Cu ions that occupy the octahedrally coordinated Nb sites and also reveal the existence of oxygen vacancy VO¨ in the nearest neighboring around the Cu atom evidently. Moreover, the Cu and Nb K-edge extended x-ray absorption fine structure clearly suggests that the oxygen vacancies should be located at two O22 sites with the two longest Cu-O22 bond lengths, thus producing trimeric bent VO¨-CuNb″′-VO¨ defect complexes with a dipole moment PD parallel to the spontaneous polarization Ps, instead of dimeric CuNb″′-VO¨ and straight VO¨-CuNb″′-VO¨ defect complexes. This kind of special defect structure is also different from that observed in conventional Pb-based perovskite ferroelectrics in which only dimeric CuTi″-VO¨ defect dipoles were observed. Finally, the influence of the defect complexes on the macroscopic properties was specially discussed by taking into account the interaction between Ps and PD.
A coarse-grained polymer model for studying the glass transition
Authors: Hsu Hsiao-Ping , Kremer Kurt
Published: March 2019

To study the cooling behavior and the glass transition of polymer melts in bulk and with free surfaces, a coarse-grained weakly semi-flexible polymer model is developed. Based on a standard bead spring model with purely repulsive interactions, an attractive potential between non-bonded monomers is added such that the pressure of polymer melts is tuned to zero. Additionally, the commonly used bond bending potential controlling the chain stiffness is replaced by a new bond bending potential. For this model, we show that the Kuhn length and the internal distances along the chains in the melt only very weakly depend on the temperature, just as for typical experimental systems. The glass transition is observed by the temperature dependency of the melt density and the characteristic non-Arrhenius slowing down of the chain mobility. The new model is set to allow for a fast switch between models, for which a wealth of data already exists.
Workfunction fluctuations in polycrystalline TiN observed with KPFM and their impact on MOSFETs variability
Authors: Ruiz A. , Seoane N. , Claramunt S. , García-Loureiro A. , Porti M. , Couso C. , Martin-Martinez J. , Nafria M.
Published: March 2019

A more realistic approach to evaluate the impact of polycrystalline metal gates on the MOSFET variability is presented. 2D experimental workfunction maps of a polycrystalline TiN layer were obtained by Kelvin Probe Force Microscopy with a nanometer resolution. These data were the input of a device simulator, which allowed us to evaluate the effect of the workfunction fluctuations on MOSFET performance variability. We have demonstrated that in the modelling of TiN workfunction variability not only the different workfunctions of the grains but also the grain boundaries should be included.
The study of operation modes of the self-magnetically insulated ion diode
Authors: Stepanov A. V. , Shamanin V. I. , Remnev G. E.
Published: March 2019

The operation modes of a self-magnetically insulated ion diode were studied. The plasma formation at the anode surface was found to be accompanied by an electron leakage current due to the bipolar high voltage pulse. The emitting anode surface and ion beam density distribution were investigated at the ion diode output area. The characteristics of the electron leakage current are presented depending on the ion diode operation mode. The area of the emitting anode surface was approximately 25%-30% of the total anode area. The electron leakage current reaches up to 6.5 kA in the ion diode.
Subwavelength coupling and ultra-high exponential gain coefficient originating from 2D electron gas at ITO/LiNbO3 interface
Authors: Wang Chao , Wang Yingce , Huo Dewang , Zhao Hua , Zhang Jingwen
Published: March 2019

Two dimensional electron gases (2DEGs) formed at interfaces between two oxides have been drawing growing attention for their intriguing magnetic, superconducting, and optical properties. Remarkable anisotropic transmission was observed from an indium-tin-oxide (ITO) coated lithium niobate (LN) slab, implying that a 2DEG is formed at one of the ITO/LN interfaces, and this is seemingly behind the anisotropic transmission. To optically probe 2DEG formation at one of the ITO/LN interfaces, the first reflected beam was monitored with one (two) laser beam(s). Reflective dynamics as large as 5%-15% were observed, pointing unambiguously to a subwavelength coupling and corresponding to, conservatively, exponential gain coefficients of −26 800 to +2700 cm−1 with half a wavelength as the coupling range. All observations are far beyond the reach of conventional bulk photorefractive effects, but align well with a picture of surface plasmon polariton excitation based on 2DEG formation. The 2DEG proximal to the LN substrate is a promising candidate for designing nonlinear plasmonics based nanometric waveguides, rectifiers, modulators, and sensors, which are compatible with current photonic circuits.
In silico characterisation and functional validation of chilling tolerant divergence 1 (COLD1) gene in monocots during abiotic stress
Authors: Anunanthini P. , Manoj V. M. , Sarath Padmanabhan T. S. , Dhivya S. , Narayan J. Ashwin , Appunu C. , Sathishkumar R.
Published: March 2019

The G protein-coupled receptor is one of the major transmembrane proteins in plants. It consists of an α subunit, a β subunit and three γ subunits. Chilling tolerant divergence 1 (COLD1) includes a Golgi pH receptor (GPHR) domain, which maintains cell membrane organisation and dynamics, along with abscisic acid linked G protein-coupled receptor (ABA_GPCR) that regulates the signalling pathways during cold stress. In the present study, we performed characterisation of a homologous COLD1 from the economically important monocot species Oryza sativa L., Zea mays L., Sorghum bicolor (L.)Moench and Erianthus arundinaceus (L.) Beauv. IK 76-81, a wild relative of Saccharum. COLD1 was isolated from E. arundinaceus IK 76-81, analysed for its evolution, domain, membrane topology, followed by prediction of secondary, tertiary structures and functionally validated in all four different monocots. Gene expression studies of COLD1 revealed differential expression under heat, drought, salinity and cold stresses in selected monocots. This is the first study on regulation of native COLD1 during abiotic stress in monocots, which has opened up new leads for trait improvement strategies in this economically important crop species.
Genomic and molecular characterization of preterm birth
Authors: Knijnenburg Theo A. , Vockley Joseph G. , Chambwe Nyasha , Gibbs David L. , Humphries Crystal , Huddleston Kathi C. , Klein Elisabeth , Kothiyal Prachi , Tasseff Ryan , Dhankani Varsha , Bodian Dale L. , Wong Wendy S. W. , Glusman Gustavo , Mauldin Denise E. , Miller Michael , Slagel Joseph , Elasady Summer , Roach Jared C. , Kramer Roger , Leinonen Kalle , Linthorst Jasper , Baveja Rajiv , Baker Robin , Solomon Benjamin D. , Eley Greg , Iyer Ramaswamy K. , Maxwell George L. , Bernard Brady , Shmulevich Ilya , Hood Leroy , Niederhuber John E.
Published: March 2019

Significance

Preterm birth (PTB) complications are the leading cause of long-term morbidity and mortality in children. The genetic and molecular characteristics of PTB and related disorders remain unclear. In this study, a family-based cohort of 791 family trios, including 270 PTB and 521 control families, was investigated by using whole-genome sequencing, RNA sequencing, and DNA methylation data. Integrative analysis identified 160 genomic variants associated with PTB-related phenotypes and led to the discovery of 72 candidate biomarker genes for very early PTB (VEPTB). The genes associated with VEPTB involve growth signaling and inflammation- and immunity-related pathways. With these data, and by stratifying PTB by subphenotype, we have identified PTB genes and pathways that can be used as a starting point in further clinical studies.
Identifying spinon excitations from dynamic structure factor of spin-1/2 Heisenberg antiferromagnet on the Kagome lattice
Authors: Zhu W. , Gong Shou-shu , Sheng D. N.
Published: March 2019

Significance

In frustrated quantum magnets, the interplay between quantum fluctuation and geometric frustration may prevent magnetic ordering and result in exotic quantum spin liquids, where the spin degrees of freedom form disordered liquid-like states with novel fractionalized excitations. Here, we study the dynamical response of spin liquids on a Kagome lattice Heisenberg antiferromagnet. Our results reproduce the main observations in the inelastic neutron scattering measurements of herbertsmithite and unveil the spin liquid nature of the ground state with fractionalized spinon excitations. By crossing the quantum-phase transition between the spin liquid and magnetically ordered phase, we identify the condensation of two-spinon bound state as the driving force.
Mapping cultural tightness and its links to innovation, urbanization, and happiness across 31 provinces in China
Authors: Chua Roy Y. J. , Huang Kenneth G. , Jin Mengzi
Published: March 2019

Significance

This study extends existing theories of cultural tightness by mapping cultural tightness and its relationship to innovation across 31 provinces in China. Consistent with prior research, we find that tighter provinces are associated with increased governmental control, constraints in daily life, religious practices, and exposure to threats. However, prior findings about cultural tightness do not fully apply to China. Departing from prior findings that tighter states are more rural, conservative, less creative, and less happy, cultural tightness in China is associated with urbanization; economic growth; better health; greater happiness; tolerance toward the lesbian, gay, bisexual, and transgender community; and gender equality. Provinces with tight cultures exhibit lower rates of substantive/radical innovation yet higher rates of incremental innovation.
Seedling traits predict drought-induced mortality linked to diversity loss
Authors: Harrison Susan , LaForgia Marina
Published: March 2019

Significance

Tremendous effort is being devoted to developing large databases of plant traits, with the hope that these constitute a species-independent currency for predicting the nature and consequences of changes to plant communities driven by climate and other impacts. Yet in strikingly few cases has the efficacy of traits for understanding observed changes to the diversity of natural communities been tested. In an annual grassland undergoing drought-induced diversity loss, we found experimentally that critical outcomes were predicted only by seedling root length, while widely measured adult and aboveground traits were weakly correlated with outcomes. The need to pinpoint traits specific to the location and timing of a major environmental stress may pose a significant challenge to trait-based ecology.
Temperature- and rigidity-mediated rapid transport of lipid nanovesicles in hydrogels
Authors: Yu Miaorong , Song Wenyi , Tian Falin , Dai Zhuo , Zhu Quanlei , Ahmad Ejaj , Guo Shiyan , Zhu Chunliu , Zhong Haijun , Yuan Yongchun , Zhang Tao , Yi Xin , Shi Xinghua , Gan Yong , Gao Huajian
Published: March 2019

Significance

Lipid vesicles such as liposomes are widely present in biological systems and drug delivery applications. Numerous studies have focused on their roles in intercellular communication, signaling, and trafficking. Little is known, however, about the correlation between temperature and transport rate of these vesicles in biological media. Here, we report a temperature- and rigidity-mediated rapid transport mechanism by which liposomes attain optimal diffusivity near a phase transition temperature. Remarkably, liposomes with phase transition temperature around the body temperature are observed to overcome multiple biological barriers and show substantial improvement in drug delivery efficacy.
A new computational drug repurposing method using established disease–drug pair knowledge
Authors: Saberian Nafiseh , Peyvandipour Azam , Donato Michele , Ansari Sahar , Draghici Sorin
Published: March 2019

Motivation

Drug repurposing is a potential alternative to the classical drug discovery pipeline. Repurposing involves finding novel indications for already approved drugs. In this work, we present a novel machine learning-based method for drug repurposing. This method explores the anti-similarity between drugs and a disease to uncover new uses for the drugs. More specifically, our proposed method takes into account three sources of information: (i) large-scale gene expression profiles corresponding to human cell lines treated with small molecules, (ii) gene expression profile of a human disease and (iii) the known relationship between Food and Drug Administration (FDA)-approved drugs and diseases. Using these data, our proposed method learns a similarity metric through a supervised machine learning-based algorithm such that a disease and its associated FDA-approved drugs have smaller distance than the other disease-drug pairs.

Results

We validated our framework by showing that the proposed method incorporating distance metric learning technique can retrieve FDA-approved drugs for their approved indications. Once validated, we used our approach to identify a few strong candidates for repurposing.

Availability and implementation

The R scripts are available on demand from the authors.

Supplementary information

Supplementary data are available at Bioinformatics online.
Do structural habitat modifications associated with urbanization influence locomotor performance and limb kinematics in Anolis lizards?
Authors: Battles Andrew C , Irschick Duncan J , Kolbe Jason J
Published: March 2019

Urbanization significantly alters habitats for arboreal species, increasing the frequency of very smooth substrates by substituting artificial objects, such as metal poles and painted walls, for some trees. Because they experience these novel substrates more often, urban animals may use strategies to overcome challenges from substrate smoothness that animals from natural habitats do not. We assessed locomotor performance and two-dimensional hindlimb kinematics of two species of Anolis lizards (Anolis cristatellus and Anolis sagrei) from both urban and natural habitats in Miami, Florida. We ran lizards on six racetracks, crossing three substrates of increasing smoothness (rough bark, concrete blocks, and smooth, unpainted wood) with two inclinations (37° and vertical). We found that on vertical tracks with smooth substrates, lizards ran slower, took shorter strides and exhibited more contracted limb postures at the end of their stance than when running on the inclined track. Urban lizards, which are likely to be exposed more often to smooth substrates, did not adjust their movement to increase performance relative to lizards from natural habitats. This result, and the similarity of kinematic strategies between the two species, suggests the locomotor responses of lizards to substrate properties are highly conserved, which may be a mitigating factor that dampens or obviates the effects of natural selection on locomotor behaviour.
Stability Kinetics of Imiquimod: Development and Validation of an Analytical Method
Authors: Sharma Mandeep , Sharma Gajanand , Singh Bhupinder , Katare O P
Published: March 2019

For a new immune modulator imiquimod, various liquid chromatography methods have been described in literature but all of them are deficient in one or other aspects of complete method development. The present work intends to develop and validate the stability indicating reverse phase high performance liquid chromatographic (HPLC) method. The isocratic flow of mobile phase comprising equal volume ratio of acetate buffer BP pH 3.7 and acetonitrile at the rate of 1.5 mL/min through the C-18 column at 25°C lead to elution of drug around 2.3 min when analyzed at 244 nm using UV-detector. The linear regression equation in calibration plot was y = 61632×-1224 with 0.9992 coefficient of determination (r2). The percent relative standard variation (% RSD) in peak area at low, mid and high region of linearity range was less than 5% in precision studies. The method was able to detect 0.039 μg/mL of drug but practical limit of quantitation (LOQ) was 1.5 μg/mL. The imiquimod molecule was stable in all except oxidizing conditions where it degraded into more polar molecule in hydrogen peroxide (H2O2) concentration dependent manner. Therefore, an analytical method capable of accurately and specifically estimating the drug in microgram range was successfully developed.
Faulting processes during early-stage rifting: seismic and geodetic analysis of the 2009–2010 Northern Malawi earthquake sequence
Authors: Gaherty J B , Zheng W , Shillington D J , Pritchard M E , Henderson S T , Chindandali P R N , Mdala H , Shuler A , Lindsey N , Oliva S J , Nooner S , Scholz C A , Schaff D , Ekström G , Nettles M
Published: March 2019

In December, 2009, a rare sequence of earthquakes initiated within the weakly extended Western Rift of the East African Rift system in the Karonga province of northern Malawi, providing a unique opportunity to characterize active deformation associated with intrabasinal faults in an early-stage rift. We combine teleseismic and regional seismic recordings of the largest events, InSAR imagery of the primary sequence, and recordings of aftershocks from a temporary (4-month) local network of six seismometers to delineate the extent and geometry of faulting. The locations of ∼1900 aftershocks recorded between January and May 2010 are largely consistent with a west-dipping normal fault directly beneath Karonga as constrained by InSAR and CMT fault solutions. However, a substantial number of epicentres cluster in an east-dipping geometry in the central part of the study area, and additional west-dipping clusters can be discerned near the shore of Lake Malawi, particularly in the southern part of the study area. Given the extensive network of hanging wall faults mapped in the Karonga region on the surface and in seismic reflection images, the distribution of events is strongly suggestive of multiple faults interacting to produce the observed deformation, and the InSAR data permit this but do not require it. We propose that fault interaction contributed to the seismic moment release as a series of Mw 5-to-6 events instead of a normal main shock–aftershock sequence. We find the depth of fault slip during the main shocks constrained by InSAR peaks at less than 6 km, while the majority of recorded aftershocks are deeper than 6 km. This depth discrepancy appears to be robust and may be explained by fault interaction. Structural complexities associated with fault interaction may have limited the extent of coseismic slip during the main shocks, which increased stress deeper than the coseismic slip zone on the primary fault and synthetic faults to the east, causing the energetic aftershock series. There is no evidence of deformation at the Rungwe volcanic province ∼50 km north of the earthquake sequence between 2007 and 2010, consistent with previous interpretations of no significant magmatic contribution during the sequence.
Optimizing effort allocation in data poor mixed fisheries
Authors: Sgardeli Vasiliki , Tserpes George , Maravelias Christos D
Published: March 2019

Management of mixed fisheries requires reconciling many different and often conflicting objectives (achieving MSY targets and ensuring economic viability among others). In multi-gear mixed fisheries, where many fleets exploit the same species, reallocation of fishing effort can optimize the biological and socioeconomic output of the fishery. Most existing effort allocation tools require extensive data for their parameterization (i.e. detailed effort data and/or analytical assessment of stock status). We present a low-data demanding effort allocation framework for fisheries managed through effort control, with minimum data requirements the surplus production assessment of key stock, catch shares and basic economic fleet data. Profit maximization is considered the overall management goal, which is constrained by single-species biological targets. The method is tested on the Aegean Sea demersal fishery, where two fleet segments exploit numerous species. To achieve sustainable exploitation for the main Aegean stocks, the total effort should be reduced by ∼30%. The framework allows integrating various biological, economic, or other objectives and provides a simple graphical illustration of the allocation result, which can provide a useful tool to convey complex information to managers. To facilitate its application, the source code developed in R programming environment is provided as a supplement.
Update on the global epidemiology of intussusception: a systematic review of incidence rates, age distributions and case-fatality ratios among children aged <5 years, before the introduction of rotavirus vaccination
Authors: Clark Andrew D , Hasso-Agopsowicz Mateusz , Kraus Matthew W , Stockdale Lisa K , Sanderson Colin F B , Parashar Umesh D , Tate Jacqueline E
Published: March 2019

Background

In some countries that have introduced oral rotavirus vaccines, a small but elevated risk of intussusception—a rare bowel disorder—has been reported. Updated estimates on the global epidemiology of intussusception are needed to help predict the potential number of intussusception cases that could be caused by the vaccine in different settings.

Methods

We estimated incidence rates, age distributions and case-fatality ratios (CFRs) for intussusception hospital admissions among children aged <5 years, before the introduction of rotavirus vaccines. We included all articles identified in a systematic review between January 2002 and January 2018, and contacted authors for more granular unpublished data on age distributions.

Results

We identified 128 articles containing 227 country datasets (61 age distributions, 71 incidence rates and 95 CFRs). The median age of intussusception ranged from 29 weeks in Africa (83% of cases in the first year of life) to 70 weeks in the Western Pacific region (35% of cases in the first year of life). The median (range) annual incidence of intussusception hospital admissions per 100 000 aged <1 year ranged from 34 (13–56) in Africa to 90 (9–380) in the Western Pacific region. We found extreme differences between the CFRs in Africa (1 death in every 10 hospital admissions) and the rest of the world (fewer than 1 death in every 100–2000 hospital admissions).

Conclusion

Intussusception epidemiology varies by country and region. Understanding and recognizing these differences will be important when assessing the potential number of intussusception cases associated with rotavirus vaccines.
Political Knowledge: Assessing the Stability of Gender Gaps Cross-Nationally
Authors: Fortin-Rittberger Jessica
Published: March 2019

This article investigates gender gaps in political knowledge by exploiting a pooled dataset containing the four modules of the Comparative Study of Electoral Systems, thereby allowing the comparison of seven different measurements of political knowledge, the most comprehensive comparison to date. The paper’s findings are threefold. First, the two conventional types of political knowledge—factual or placement knowledge—belong to different latent constructs and are not interchangeable. Second, most factual knowledge scales produce important variations in the size of gender gaps across and within countries over time. Third, “don’t know” as an incorrect response generally leads to broader gender gaps, given men’s higher propensity to guess.
Validation of a Fully Automated Immunoaffinity Workflow for the Detection and Quantification of Insulin Analogs by LC–MS-MS in Postmortem Vitreous Humor
Authors: Legg Kevin M , Labay Laura M , Aiken Sally S , Logan Barry K
Published: March 2019

The analysis of biological specimens collected at autopsy for the presence of exogenous insulin(s) is of special interest in select death investigations as they may be suspected in the cause of a death. Technical challenges include the limited stability of insulin, and the forensic requirement of differentiating endogenous insulin from pharmaceutical analogs. A novel method was developed for the detection and quantification of human insulin, Glulisine, Lispro, Aspart, Glargine and Detemir in vitreous fluid. An immunoaffinity extraction procedure is performed followed by separation of the insulin α- and β-chains. Liquid chromatography tandem mass spectrometry analysis of the β-chain allows for the unequivocal identification of each insulin analog. The analytical measurement range for each insulin was 0.5–25 ng/mL. The method was evaluated for accuracy, precision, carryover, interferences and stability. Eight vitreous fluid samples collected from cases where untoward insulin use was suspected were subjected to analysis. Positive results were obtained from three samples, and a detailed case history is provided for one of these cases. Even though insulin instability in postmortem biological fluid remains a challenge, this method allows for a reliable forensic-level analysis in vitreous fluid.
Chemosystematics Using Cuticular Compounds: A Powerful Tool to Separate Species in Mediterranean Dung Beetles (Coleoptera: Geotrupidae)
Authors: Niogret Jerome , Felix Anne-Emmanuelle , Nicot Antoine , Lumaret Jean-Pierre
Published: March 2019

The use of chemical characters to infer a phylogeny is known to be promising to ascertain phylogenetic relationships in controversial groups. Dung beetle classifications containing the Geotrupidae family, based on morphological characters and genes, are debated with respect to the subfamilies, such as the Bolboceratids. In our study, we used different approaches to generate and compare the Geotrupidae phylogenies based on genetics and chemotaxonomy. Cuticular compounds were analyzed for 12 species of Mediterranean dung beetles to build a chemical phylogeny. In addition, mitochondrial and nuclear marker concatenation have been used to elaborate the molecular phylogeny. Using the cuticular compound continuous data, our results showed that each species was associated with a specific chemical pattern and that all individuals belonging to the same species displayed a similar chemical blend. The most distant species was Bolbelasmus gallicus, with an evident distinction from the other species due to several compounds. The maximum parsimony tree showed that all genera belonging to a Geotrupidae subfamily were grouped in the same clade, with B. gallicus species isolated in another clade, similar to the chemotaxonomy grouping. A strong positive correlation between chemotaxonomy and genetic phylogeny has been demonstrated, underlying a genetic basis for cuticular hydrocarbon variations. Our results are congruent with previous studies using morphological or genetic data. Our results also showed that only 10 compounds can be used to distinguish at least six species of dung beetle and that chemotaxonomy could become a useful and affordable tool to determine phylogenetic relationships in insects.
Inferences on the timeline of reionization at z ∼ 8 from the KMOS Lens-Amplified Spectroscopic Survey
Authors: Mason Charlotte A , Fontana Adriano , Treu Tommaso , Schmidt Kasper B , Hoag Austin , Abramson Louis , Amorin Ricardo , Bradač Maruša , Guaita Lucia , Jones Tucker , Henry Alaina , Malkan Matthew A , Pentericci Laura , Trenti Michele , Vanzella Eros
Published: March 2019

Detections and non-detections of Lyman alpha (Lyα) emission from z > 6 galaxies (<1 Gyr after the big bang) can be used to measure the timeline of cosmic reionization. Of key interest to measuring reionization’s mid-stages, but also increasing observational challenge, are observations at z > 7, where Lyα redshifts to near infra-red wavelengths. Here we present a search for z > 7.2 Lyα emission in 53 intrinsically faint Lyman Break Galaxy candidates, gravitationally lensed by massive galaxy clusters, in the KMOS Lens-Amplified Spectroscopic Survey (KLASS). With integration times of ∼7–10 h, we detect no Lyα emission with signal-to-noise ratio (S/N) > 5 in our sample. We determine our observations to be 80 per cent complete for 5σ spatially and spectrally unresolved emission lines with integrated line flux >5.7 × 10−18 erg s−1 cm−2. We define a photometrically selected sub-sample of 29 targets at z = 7.9 ± 0.6, with a median 5σ Lyα EW limit of 58 Å. We perform a Bayesian inference of the average intergalactic medium (IGM) neutral hydrogen fraction using their spectra. Our inference accounts for the wavelength sensitivity and incomplete redshift coverage of our observations, and the photometric redshift probability distribution of each target. These observations, combined with samples from the literature, enable us to place a lower limit on the average IGM neutral hydrogen fraction of $\gt 0.76 \,\, (68{{\ \rm per\ cent}}), \,\, \gt 0.46 \,\, (95{{\ \rm per\ cent}})$ at z ∼ 8, providing further evidence of rapid reionization at z ∼ 6–8. We show that this is consistent with reionization history models extending the galaxy luminosity function to $M_ \rm {\small UV}\lesssim -12$, with low ionizing photon escape fractions, $f_\textrm{esc} \lesssim 15{{\ \rm per\ cent}}$.
Reduction in acute kidney injury stage predicts survival in patients with type-1 hepatorenal syndrome
Authors: Wong Florence , Boyer Thomas D , Sanyal Arun J , Pappas Stephen C , Escalante Shannon , Jamil Khurram
Published: March 2019

Background

Hepatorenal syndrome type 1 (HRS-1), a form of acute kidney injury (AKI) in cirrhosis, has a median survival of days to weeks if untreated. The impact of reduction in AKI stage on overall survival in cirrhosis, independent of HRS reversal, is unclear.

Methods

The Randomized, placEbo-controlled, double-blind study to confirm the reVERSal of HRS-1 with terlipressin study assessed terlipressin versus placebo, both with albumin, as treatment for HRS-1 for ≤14 days. Renal dysfunction severity was categorized by AKI stage at enrollment. Baseline patient characteristics were evaluated as predictors of AKI improvement using a multivariate model; the association between AKI stage reduction and 90-day survival was assessed using linear regression.

Results

A total of 184 patients (terlipressin: n = 91; placebo: n = 93) with similar numbers in AKI Stages 1–3 (terlipressin/placebo, Stage 1: n = 25/26; Stage 2: n = 35/33; Stage 3: n = 31/34) were included. Predictors of AKI improvement were absence of alcoholic hepatitis, baseline serum creatinine and male gender. Overall survival was not significantly different across AKI stages (range 53–65%). In patients with no AKI worsening, 90-day survival was consistently better when AKI improved independent of HRS reversal, regardless of the initial AKI stage, with patients with Stage 1 at initial diagnosis achieving the greatest clinical benefit. A significant association was observed between AKI reduction and overall 90-day survival (P = 0.0022).

Conclusions

A reduction in AKI stage, independent of HRS reversal, was sufficient to improve overall survival in patients with HRS-1. The goal for HRS-1 treatment should be less stringent than absolute HRS reversal.
Linking atmospheric pollution to cryospheric change in the Third Pole region: current progress and future prospects
Authors: Kang Shichang , Zhang Qianggong , Qian Yun , Ji Zhenming , Li Chaoliu , Cong Zhiyuan , Zhang Yulan , Guo Junming , Du Wentao , Huang Jie , You Qinglong , Panday Arnico K , Rupakheti Maheswar , Chen Deliang , Gustafsson Örjan , Thiemens Mark H , Qin Dahe
Published: March 2019

The Tibetan Plateau and its surroundings are known as the Third Pole (TP). This region is noted for its high rates of glacier melt and the associated hydrological shifts that affect water supplies in Asia. Atmospheric pollutants contribute to climatic and cryospheric changes through their effects on solar radiation and the albedos of snow and ice surfaces; moreover, the behavior and fates within the cryosphere and environmental impacts of environmental pollutants are topics of increasing concern. In this review, we introduce a coordinated monitoring and research framework and network to link atmospheric pollution and cryospheric changes (APCC) within the TP region. We then provide an up-to-date summary of progress and achievements related to the APCC research framework, including aspects of atmospheric pollution's composition and concentration, spatial and temporal variations, trans-boundary transport pathways and mechanisms, and effects on the warming of atmosphere and changing in Indian monsoon, as well as melting of glacier and snow cover. We highlight that exogenous air pollutants can enter into the TP’s environments and cause great impacts on regional climatic and environmental changes. At last, we propose future research priorities and map out an extended program at the global scale. The ongoing monitoring activities and research facilitate comprehensive studies of atmosphere–cryosphere interactions, represent one of China's key research expeditions to the TP and the polar regions and contribute to the global perspective of earth system science.
The decline in volatility in the US economy. A historical perspective
Authors: Gadea María Dolores , Gómez-Loscos Ana , Pérez-Quirós Gabriel
Published: March 2019

In this paper, we analyse the volatility of US GDP growth using quarterly series starting in 1875. We find structural breaks in volatility at the end of World War II and at the beginning of the Great Moderation period. We show that the Great Moderation volatility reduction is only linked to changes in expansions, whereas that after World War II is due to changes in both expansions and recessions. We also propose several methodologies to date the US business cycle in this long period. We find that taking volatility into account improves the characterization of the business cycle.
Small-scale motions in solar filaments as the precursors of eruptions
Authors: Seki Daikichi , Otsuji Kenichi , Isobe Hiroaki , Ishii Takako T , Ichimoto Kiyoshi , Shibata Kazunari
Published: March 2019

Filaments, the dense cooler plasma floating in the solar corona supported by magnetic fields, generally exhibit certain activations before they erupt. In our previous study (Seki et al. 2017, ApJ, 843, L24), we observed that the standard deviation of the line-of-sight (LOS) velocities of the small-scale motions in a filament increased prior to its eruption. However, because that study only analyzed one event, it is unclear whether such an increase in the standard deviation of LOS velocities is common in filament eruptions. In this study, 12 filaments that vanished in Hα line center images were analyzed in a manner similar to the one in our previous work; these included two quiescent filaments, four active region filaments, and six intermediate filaments. We verified that in all the 12 events, the standard deviation of the LOS velocities increased before the filaments vanished. Moreover, we observed that the quiescent filaments had approximately 10 times longer duration of an increase in the standard deviation than the other types of filaments. We concluded that the standard deviation of the LOS velocities of the small-scale motions in a filament can potentially be used as a precursor of a filament eruption.
Growth curves: The experiences of Canadian paediatricians in their first 5 years of independent practice
Authors: Schrewe Brett , Patel Rikin , Rowan-Legg Anne
Published: March 2019

Objectives

Completing training is a rite of passage common to all physicians, yet our knowledge of the components in postgraduate paediatric education that equip learners for successful transition to practice is limited. In order to optimally design training programs, it is critical to develop a better sense of what early career paediatricians (ECPs) experience as they navigate this time of transition.

Methods

We created and distributed a 23-question survey via e-mail to 481 Canadian ECPs in September 2017, specifically to those who received Royal College certification in 2011 or later. Survey responses were obtained confidentially through an online platform (Survey Monkey). Descriptive statistics and thematic analysis were used to analyze responses to closed-ended and free text questions, respectively.

Results

Response rate was 42% with nearly 70% of the respondents self-identifying as general paediatricians. Factors facilitating transition to practice included: dedicated mentorship; supportive new colleagues and workplace environment; and ease of finding work. Identified challenges included: billing, finances, and practice management; adjusting to a different scope of practice and learning local resources; managing comfort level; and achieving work–life balance. Nearly half of the respondents expressed interest in mentoring new ECP colleagues.

Conclusions

Our findings suggest that ECPs find clear value in mentorship, but desire further support to adapt to new practice contexts and activities. As a result, we must consider strategies in both individual programs and nationally that effectively prepare learners prior to transition and align with needs in the first years of independent practice.
Hyperalgesia and Central Sensitization Signs in Patients with Cluster Headache: A Cross-Sectional Study
Authors: Gil-Martínez Alfonso , Navarro-Fernández Gonzalo , Mangas-Guijarro María Ángeles , Díaz-de-Terán Javier
Published: March 2019

Objective

To investigate central sensitization (CS) in cluster headache (CH) and to evaluate its relationship with disease characteristics and psychological comorbidities.

Design

Cross-sectional study.

Settings

Whether CS occurs in CH, as it does in other primary headaches, is a subject of debate. Few studies have evaluated the presence of CS and its relationship with psychological comorbidities in patients with CH.

Subjects

Twenty patients with episodic or chronic CH and 16 healthy controls were recruited.

Methods

The variables evaluated included frequency, intensity and duration of headache attacks, pressure pain thresholds (PPTs) and wind-up (WU) ratios of pain bilaterally measured over trigeminal and extratrigeminal areas, and results of questionnaires regarding anxiety and depression (Hospital Anxiety and Depression Scale [HADS], Beck Depression Inventory [BDI], State-Trait Anxiety Inventory [STAI]), quality of life (Short Form-36 [SF-36]), headache impact (Headache Impact Test [HIT-6]), and allodynia (Allodynia Symptom Checklist [ASC]).

Results

PPT levels were significantly lower in the CH group compared with the healthy participants (all tested points, P < 0.001). No differences were found in WU ratios between groups. However, differences in HADS (P < 0.01), BDI (P < 0.01), STAI (P < 0.01), SF-36 (P < 0.01), HIT-6 (P < 0.001), and ASC (P < 0.01) were observed between groups. The healthy group showed a moderate negative correlation between SF-36 and BDI (rho = –0.59, P = 0.03). Likewise, the CH group showed a moderate negative correlation between frequency and BDI (rho = –0.52, P = 0.03), a strong positive correlation between duration and HADS (rho = 0.86, P < 0.01), and a moderate negative correlation between intensity and PPT over symptomatic V1 (rho = –0.66, P < 0.01) and over asymptomatic V1 (rho = –0.65, P < 0.01). The CH group also showed a moderate negative correlation between SF-36 and anxiety and depression variables.

Conclusions

Our findings show that patients with CH have lower PPT levels at cranial and extracranial points, suggesting, as in other primary headaches, the presence of CS. We have also found a high prevalence of psychiatric comorbidities that correlate with the length and frequency of attacks. These findings highlight the importance of a multidisciplinary approach to the treatment of patients with CH.
Plant-Pathogenic Agrobacterium tumefaciens Strains Have Diverse Type VI Effector-Immunity Pairs and Vary in In-Planta Competitiveness
Authors: Wu Chih-Feng , Santos Mary Nia M. , Cho Shu-Ting , Chang Hsing-Hua , Tsai Yi-Ming , Smith Delaney A. , Kuo Chih-Horng , Chang Jeff H. , Lai Erh-Min
Published: March 2019

The type VI secretion system (T6SS) is used by gram-negative bacteria to translocate effectors that can antagonize other bacterial cells. Models predict the variation in collections of effector and cognate immunity genes determine competitiveness and can affect the dynamics of populations and communities of bacteria. However, the outcomes of competition cannot be entirely explained by compatibility of effector-immunity (EI) pairs. Here, we characterized the diversity of T6SS loci of plant-pathogenic Agrobacterium tumefaciens and showed that factors other than EI pairs can impact interbacterial competition. All examined strains encode T6SS active in secretion and antagonism against Escherichia coli. The spectra of EI pairs as well as compositions of gene neighborhoods are diverse. Almost 30 in-planta competitions were tested between different genotypes of A. tumefaciens. Fifteen competitions between members of different species-level groups resulted in T6SS-dependent suppression in in-planta growth of prey genotypes. In contrast, ten competitions between members within species-level groups resulted in no significant effect on the growth of prey genotypes. One strain was an exceptional case and, despite encoding a functional T6SS and toxic effector protein, could not compromise the growth of the four tested prey genotypes. The data suggest T6SS-associated EI pairs can influence the competitiveness of strains of A. tumefaciens, but genetic features have a significant role on the efficacy of interbacterial antagonism.