bluuebunny/crossref_metadata_2025 huggingface dataset:
Extremely Slow Decay of Yellow Luminescence in Be‐Doped GaN and Its Identification
Authors: Lamprecht Matthias , Thonke Klaus , Teisseyre Henryk , Boćkowski Michał
Published: August 2018

The extremely slowly decaying yellow luminescence band around 2.08 eV in GaN:Be:O is studied by continuous‐wave and time‐resolved photoluminescence, as well as photoluminescence excitation spectroscopy and absorption. The lifetime obtained for this process is around 2.2 s and is thermally quenched for temperatures between 250 and 400 K. From the photoluminescence excitation measurements, two major pumping thresholds at around 2.7 and 3.1 eV can be identified. We discuss the origin of the Be‐related 2.08 eV transition as well as the origin of the overlaying photoluminescence bands at 1.88 and 2.12 eV.
Structural and electronic properties of the Al4Sr(001) surface: A first‐principles study
Authors: Li Xundu , Li Ke , Wei Chunhui
Published: August 2018

Surface structure, surface energy, surface grand potential, and electronic structure of Al‐ and Sr‐terminated Al4Sr(001) surfaces were analyzed using a first‐principles method based on density functional theory. It is revealed that the effects of relaxation are mainly localized within the top three atomic layers for both terminations, and the largest change in interlayer spacing occurs at the first layer of the Sr‐terminated surface. The surface energy calculation results indicate that the Al‐terminated surface is more stable, and the Sr‐terminated surface is more active. The higher surface energy comes from the unsaturated chemical bonds existing on the surface. In the ideal metallic system of Al‐Sr, the grand potential of the Sr‐terminated surface is lower than that of the Al‐terminated surface, indicating that the Sr‐terminated surface could be more readily observed under experimental conditions. The two terminations of Al4Sr(001) exhibit both metallic and covalent features, as does bulk Al4Sr.
Toward Tailorable Zn‐Ion Textile Batteries with High Energy Density and Ultrafast Capability: Building High‐Performance Textile Electrode in 3D Hierarchical Branched Design
Authors: Zhao Tao , Zhang Guoming , Zhou Fangshuo , Zhang Sen , Deng Chao
Published: August 2018

Rechargeable Zn‐ion batteries are promising candidates for wearable energy storage devices. However, their performance is severely restricted by the low conductivity and inferior mass loading. Herein, a new type of the textile based electrodes with 3D hierarchical branched design is reported. Both Ni nanoparticles and carbon nanotubes are used to build conductive coatings on the textiles. The 3D hierarchical nanostructures, consisting of the vertical‐aligned nanosheets and the fluffy‐like small flakes, grow on the conductive textiles to form the self‐supported electrodes. It ensures fast electron/ion transport and high mass loading, and maintains the structure stability during cycling. Two textile electrodes with the NiCo hydroxide and MnO2 self‐branched nanostructures are constructed. Their faster kinetics, higher capacity and better rate capability than the solitary nanosheets based counterpart demonstrate the superiority of the hierarchical architecture. Moreover, the solid‐state Zn‐MnO2 and Zn‐NiCo batteries are fabricated based on the textile electrodes and the polymer electrolytes. The high energy density, superior power density and good long‐term cycling stability confirm their excellent energy storage ability and fast charge/discharge capability. Particularly, the high safety under various conditions enable them promising candidates for wearable electronics.
Reformation Behavior of Austenite in 2205 Duplex Stainless Steel with Rapid Heat Treatment
Authors: Wu Tianhai , Wang Jianjun , Li Huabing , Jiang Zhouhua , Liu Chunming , Zhang Hongyang
Published: August 2018

The reformation behavior of austenite in coarsened ferrite grains of 2205 duplex stainless steel is studied by means of rapid heat treatment process. With the prolongation of peak temperature holding time, ferrite grains coarsen significantly from 200 µm at 1 s to over 1000 µm at 10 min, and the reformation of grain boundary austenite is suppressed while fine equiaxed intragranular austenite is promoted during the subsequent isothermal treatment at 850 °C owing to the reduction of total ferrite grain boundary area. With the decreasing of isothermal temperature, the microstructure evolution of reformed austenite from widmanstatten austenite to acicular austenite and finally to equiaxed austenite is observed, due to the increasing of the nucleation site density. The orientation relationships (OR) between reformed austenite and ferrite vary at different isothermal temperatures. The N‐W OR gradually changes into the K‐S OR with the increasing of isothermal temperature to lower the coherent elastic strain energy induced in ferrite matrix.
Seismic performance factors for low‐ to mid‐rise steel diagrid structural systems
Authors: Asadi Esmaeel , Adeli Hojjat
Published: August 2018

Diagrids are known as an esthetically pleasing and structurally efficient system. The current design codes and provisions, however, provide no specific guidelines for their design under extreme events such as earthquakes. This paper presents a comprehensive investigation of the performance of steel diagrid structures to evaluate their key seismic performance factors. Nonlinear static, time‐history dynamic, and incremental dynamic analyses are used to assess diagrid performance and collapse mechanisms in a high seismic region. Seismic performance factors including response modification factor, ductility factor, overstrength factor, and deflection amplification factor are quantified using 4 different methodologies. Four archetype groups of diagrid buildings ranging in height from 4 to 30 stories have been investigated. An R factor in the range of 4 to 5 is recommended for steel diagrid frames in the range of 8 to 30 stories unless supplementary analyses are conducted to find the optimal diagonal angle. For low‐rise steel diagrids (under 8 stories), an R factor in the range of 3.5 to 4 is recommended. Further, an overstrength and ductility of 2.5 and 2 are recommended. This paper lays the groundwork for including steel diagrids in design provisions.
The value of radiography in the follow-up of extremity fractures: a systematic review
Authors: van Gerven P. , Rubinstein S. M. , Nederpelt C. , Termaat M. F. , Krijnen P. , van Tulder M. W. , Schipper I. B.
Published: August 2018

Background

The added value of routine radiography in the follow-up of extremity fractures is unclear. The aim of this systematic review was to create an overview of radiography use in extremity fracture care and the consequences of these radiographs for the treatment of patients with these fractures.

Materials and methods

Studies were included if they reported on the use of radiography in the follow-up of extremity fractures and on its influence on treatment strategy, clinical outcome, or complications. A comprehensive search of electronic databases (i.e., PubMed, Embase, and Cochrane) was performed to identify relevant studies. Methodological quality was assessed with the Newcastle–Ottawa scale for cohort studies. Level of evidence was assessed using GRADE. The search, quality appraisal, and data extraction were performed independently by two researchers.

Results

Eleven studies were included. All studies were retrospective cohorts. Of these, only two used a comparative design. Two of the included studies described fractures of both the upper and lower extremities, four studies concerned fractures of the lower extremity only, and five studies focused on fractures of the upper extremity. Pooling of data was not performed because of clinical heterogeneity. Eight studies reported on a change in treatment strategy related to radiography. Percentages ranged from 0 to 2.6%. The overall results indicated that radiographs in the follow-up of extremity fractures seldom alter treatment strategy, that the vast majority of follow-up radiographs are obtained without a clinical indication and that detection of a complication on a radiograph, in the absence of clinical symptoms, is unlikely. All included studies were regarded of a ‘very low’ level using GRADE.

Conclusions

Based on current literature, the added value of routine radiography in the follow-up of extremity fractures seems limited. Results, however, should be interpreted with care, considering that available evidence is of a low level.
Editorial
Authors: Mansfield-Devine Steve
Published: August 2018

For years, vendors and specialists have been pushing two-factor authentication (2FA) as the answer to our security woes. But it seems that not all 2FA solutions are quite up to the job.
Policy-making under uncertainty
Authors: SUTHERLAND RORY
Published: August 2018

The problem with decision-making in an institutional setting is that it is often more important for one's reputation and job security to appear to be logical than it is to be truly effective. Indeed, a far lower burden of proof is applied to ideas and suggestions that accord with simple economic axioms than to those that are oblique, counterintuitive or employ second-order thinking. Hence, the best new ideas generated by behavioural science will and should often lie outside the bureaucrat's natural comfort zone; any difficulties encountered by behavioural scientists should not surprise us: like the sting of an antiseptic, they are proof that the treatment is working.
Subgroup Correspondences
Authors: Kaliszewski S. , Larsen Nadia S. , Quigg John
Published: August 2018

For a closed subgroup of a locally compact group the Rieffel induction process gives rise to aC*-correspondence over theC*-algebra of the subgroup. We study the associated Cuntz–Pimsner algebra and show that, by varying the subgroup to be open, compact, or discrete, there are connections with the Exel–Pardo correspondence arising from a cocycle, and also with graph algebras.
The identification and genetic diversity of endophytic bacteria isolated from selected crops
Authors: Woźniak M. , Gałązka A. , Grządziel J. , Głodowska M.
Published: August 2018

A collection of 45 isolates was created based on bacteria isolated from maize, broad bean, wheat, rye and wild plants such as horsetail and burdock. The aim of the current study was to isolate the bacteria, and then identify and assess the degree of genomic diversity. The molecular identification of microsymbionts isolated from the endosphere (root and stem) of plants grown in agricultural soils was performed using 16S rRNA gene sequencing. To evaluate the genomic diversity between strains that occurred in multiple host plants, 18 bacterial isolates representing four species were subjected to denaturing gradient gel electrophoresis. The 16S rDNA analysis assigned all bacterial isolates to ten genera, from whichRhizobiumwas represented by 19 isolates,Delftiaby 11,Agrobacteriumby five,Stenotrophomonasby three,Brevundimonasby two andNovosphingobium,Variovorax, Collimonas, AchromobacterandComamonasby only one isolate. Furthermore, the genomic diversity of the 11 isolates ofDelftiasp. was assessed using the BOX – polymerase chain reaction (BOX-PCR) and enterobacterial repetitive intergenic consensus – PCR (ERIC-PCR) methods. Typing patterns and analysis using BOX-PCR and ERIC-PCR data demonstrated similarities among the tested isolates. In general, the results obtained with BOX-PCR and ERIC-PCR were in good agreement. However, a greater degree of differentiation patterns of the genomic DNA was obtained in the ERIC-PCR method.
MODELING EXPERIMENTAL DATA WITH POLYNOMIALS CHAOS
Authors: Gayrard Emeline , Chauvière Cédric , Djellout Hacène , Bonnet Pierre
Published: August 2018

Given a raw data sample, the purpose of this paper is to design a numerical procedure to model this sample under the form of polynomial chaos expansion. The coefficients of the polynomial are computed as the solution to a constrained optimization problem. The procedure is first validated on samples coming from a known distribution and it is then applied to raw experimental data of unknown distribution. Numerical experiments show that only five coefficients of the Chaos expansions are required to get an accurate representation of a sample.
Analyse comparative deça fait que, alors, doncetsoà Montréal et à Welland: mutations sociales, convergences, divergences en français laurentien
Authors: BLONDEAU HÉLÈNE , MOUGEON RAYMOND , TREMBLAY MIREILLE
Published: August 2018

La présente étude compare l’évolution récente du français parlé à Montréal et celle du français parlé à Welland (Ontario) où réside une minorité francophone. Le phénomène variationnel retenu est l'emploi des connecteurs(ça) fait (que),so,alorsetdonc. Les corpus utilisés ont été recueillis à l'aide d'entretiens enregistrés de 2011 à 2015 parmi des échantillons de locuteurs stratifiés selon l’âge, la classe sociale et le sexe. L'analyse des données révèle des différences marquées dans l’évolution de ces connecteurs dans les deux communautés. Par exemple, à Montréal on observe une forte montée de(ça) fait (que)et l'obsolescence d'alorset à Welland, une forte montée deso(forme absente à Montréal), le net déclin de(ça) fait (que)et le maintien relatif d'alorsetdonc. L’étude de la configuration sociale de la variation montre plusieurs points de convergence entre les deux variétés de français laurentien (ex. association de(ça) fait (que)avec les locuteurs de la CSE basse et d'alorsavec ceux de la CSE haute). Toutefois, l'analyse de l'effet combiné des facteurs âge, CSE, sexe et bilinguisme sur la variation met au jour des différences importantes entre les deux parlers et l’émergence de normes endogènes divergentes.
Analysis of Robin Hood and Other Hashing Algorithms Under the Random Probing Model, With and Without Deletions
Authors: POBLETE P. V. , VIOLA A.
Published: August 2018

Thirty years ago, the Robin Hood collision resolution strategy was introduced for open addressing hash tables, and a recurrence equation was found for the distribution of its search cost. Although this recurrence could not be solved analytically, it allowed for numerical computations that, remarkably, suggested that the variance of the search cost approached a value of 1.883 when the table was full. Furthermore, by using a non-standard mean-centred search algorithm, this would imply that searches could be performed in expected constant time even in a full table.

In spite of the time elapsed since these observations were made, no progress has been made in proving them. In this paper we introduce a technique to work around the intractability of the recurrence equation by solving instead an associated differential equation. While this does not provide an exact solution, it is sufficiently powerful to prove a bound of π2/3 for the variance, and thus obtain a proof that the variance of Robin Hood is bounded by a small constant for load factors arbitrarily close to 1. As a corollary, this proves that the mean-centred search algorithm runs in expected constant time.

We also use this technique to study the performance of Robin Hood hash tables under a long sequence of insertions and deletions, where deletions are implemented by marking elements as deleted. We prove that, in this case, the variance is bounded by 1/(1−α), where α is the load factor.

To model the behaviour of these hash tables, we use a unified approach that we apply also to study the First-Come-First-Served and Last-Come-First-Served collision resolution disciplines, both with and without deletions.
Dual-Pivot Quicksort: Optimality, Analysis and Zeros of Associated Lattice Paths
Authors: AUMÜLLER MARTIN , DIETZFELBINGER MARTIN , HEUBERGER CLEMENS , KRENN DANIEL , PRODINGER HELMUT
Published: August 2018

We present an average-case analysis of a variant of dual-pivot quicksort. We show that the algorithmic partitioning strategy used is optimal, that is, it minimizes the expected number of key comparisons. For the analysis, we calculate the expected number of comparisons exactly as well as asymptotically; in particular, we provide exact expressions for the linear, logarithmic and constant terms.

An essential step is the analysis of zeros of lattice paths in a certain probability model. Along the way a combinatorial identity is proved.
Time trends in suicide rates by domestic gas or car exhaust gas inhalation in Japan, 1968–1994
Authors: Yoshioka E. , Hanley S. J. B. , Saijo Y.
Published: August 2018

Aims

A reduction in the carbon monoxide content of domestic gas and car exhaust gas has been associated with a decrease in gassing suicides in many western countries. In Japan, a reduction in the carbon monoxide content of domestic gas supply began in the early 1970s, and carbon monoxide emissions standards of new passenger cars were significantly strengthened in 1978. However, little is known about the impact of detoxification of these gases on gassing-related suicides in Japan. Therefore, we examined the changing patterns of suicide due to domestic gas or car exhaust gas inhalation by gender and age in Japan between 1968 and 1994.

Methods

Suicide mortality data were obtained from the Vital Statistics of Japan. In this study, age was divided into four groups: 15–24, 25–44, 45–64 and 65+ years. Method of suicide was divided into three groups: domestic gas, car exhaust gas and non-gases. We calculated method-specific age-standardised suicide rates by gender within each of the four age groups. We applied joinpoint regression to the data and quantified the observed changes.

Results

Suicide rates by domestic gas, regardless of gender and age, increased from 1968 to the mid-1970s and then decreased sharply. The proportion of all suicides accounted for by domestic gas was comparatively high in the mid-1970s among females aged 15–24 and 25–44 years, while for other gender-age-groups the proportion of domestic gas suicides remained small, even at the peak. For females aged 15–44 years, the decrease in domestic gas suicides appeared to cause a substantial decrease in overall suicides in this gender/age group. Car exhaust gas was a more common method for males, particularly those aged 25–64 years. Car exhaust gas suicide rates for males aged 25–64 years peaked in the mid-1980s, followed by a sharp decrease.

Conclusions

A reduction in the carbon monoxide content of the domestic gas, which began in the early 1970s in Japan, was associated with a decrease in domestic gas suicides for both genders of all ages. Concerning females aged 15–44 years, a decrease in domestic gas suicides caused a substantial decrease in overall suicides in this gender/age group since the proportion of domestic gas suicides among all suicides combined was comparatively large. However, it remains uncertain whether the introduction of catalytic converters in the 1970s in Japan resulted in a reduction of suicides from car exhaust gas inhalation.
Förderung basisnumerischer Kompetenzen mit einem regelbasierten Spiel im Einzel- und Gruppensetting
Authors: Skillen Johanna , Berner Valérie-D. , Ricken Gabi , Seitz-Stein Katja
Published: August 2018

Zusammenfassung. Ziel der vorliegenden Studie war die Überprüfung eines regelbasierten Zahlenbrettspiels zur Förderung von vorschulischem Zahlen- und Mengenwissen im Einzel- und Gruppensetting. Realisiert wurde ein Prä-Post-Follow-up-Design mit zwei Fördergruppen und einer Kontrollgruppe. 69 Vorschulkinder im Alter von 5 bis 6 Jahren spielten entweder vier Mal das Zahlenbrettspiel Haus der Zahlen in einer Einzel- oder Gruppenspielbedingung oder gehörten zu einer passiven Kontrollgruppe. Die Ergebnisse zeigen, dass Vorschulkinder, die in der Einzelspielbedingung am Spiel teilnahmen, stabile Verbesserungen der basisnumerischen Kompetenzen gegenüber der Kontrollgruppe aufwiesen. Die Kinder der Gruppenspielbedingung unterschieden sich dagegen in ihrer Leistung nicht von den Kindern der Kontrollgruppe, aber auch nicht von denen der Einzelspielbedingung. Die Ergebnisse werden mit Blick auf die Weiterentwicklung von Zahlenbrettspielen zur Nutzbarmachung im institutionellen Setting diskutiert.
Wie geht's dir im Kindergarten?
Authors: Sommer-Himmel Roswitha , Titze Karl
Published: August 2018

Zusammenfassung. Der Beitrag stellt ein multimethodisches und modulares Instrument zur Befragung von Kindern zur Wahrnehmung ihrer Kita vor: Kinder bewerten ihren Kindergarten, KbiK ( Sommer-Himmel, Titze & Imhof, 2016 ). Die theoretische Konzeption und Entwicklung des Instruments sowie ausgewählte Ergebnisse werden dargestellt. Der KbiK fokussiert die Partizipationsmöglichkeiten, die Bewertung der pädagogischen Angebote, das allgemeine Wohlbefinden sowie die Qualität der sozialen Kontakte in der Kita aus Sicht der Kinder und orientiert sich dabei an deren Alltagserfahrungen. Befragt wurden 53 randomisiert ausgewählte Mädchen und Jungen im Alter von fünf bis sechs Jahren aus 13 Einrichtungen. 83% der Kinder bewerteten die pädagogischen Angebote gut oder sehr gut, jedoch fanden nur 47%, dass sie eigene Ideen zu den Projekten beitragen dürfen. Die dargestellten Ergebnisse zeigen zudem exemplarisch, dass die Antworten der Kinder einen differenzierten Blick auf die Bewertung ihrer Aktivitäten und erfahrene Möglichkeiten zur Partizipation in der Kita ermöglichen. Das zusammenfassende Bewertungsrating machte deutlich, dass der weit überwiegenden Mehrheit der Kinder die pädagogischen Angebote gut oder sehr gut gefielen. Die anschließende offene Frage eruierte, was sie an den Projekten gut fanden: Etwas selbst machen/mitbestimmen (n = 10), Spaß & Freude (n = 5), Bewegung (n = 4) und kognitive Herausforderung (n = 2). Ein Drittel der Kinder (34%) nannte Ideen für weitere Projekte, insbesondere zu den Themen Tiere und Kreativprojekte. Insgesamt hat sich der KbiK in einer ersten Studie als praxistauglich und kindgemäße Methode bewährt.
An Ensemble Version of the E‐OBS Temperature and Precipitation Data Sets
Authors: Cornes Richard C. , van der Schrier Gerard , van den Besselaar Else J. M. , Jones Philip D.
Published: August 2018

We describe the construction of a new version of the Europe‐wide E‐OBS temperature (daily minimum, mean, and maximum values) and precipitation data set. This version provides an improved estimation of interpolation uncertainty through the calculation of a 100‐member ensemble of realizations of each daily field. The data set covers the period back to 1950 and provides gridded fields at a spacing of 0.25∘ × 0.25∘ in regular latitude/longitude coordinates. As with the original E‐OBS data set, the ensemble version is based on the station series collated as part of the ECA&D initiative. Station density varies significantly over the domain, and over time, and a reliable estimation of interpolation uncertainty in the gridded fields is therefore important for users of the data set. The uncertainty quantified by the ensemble data set is more realistic than the uncertainty estimates in the original version, although uncertainty is still underestimated in data‐sparse regions. The new data set is compared against the earlier version of E‐OBS and against regional gridded data sets produced by a selection of National Meteorological Services. In terms of both climatological averages and extreme values, the new version of E‐OBS is broadly comparable to the earlier version. Nonetheless, users will notice differences between the two E‐OBS versions, especially for precipitation, which arises from the different gridding method used.
Following the terrestrial tracks of Caulobacter - redefining the ecology of a reputed aquatic oligotroph
Authors: Wilhelm Roland C
Published: August 2018

For the past 60 years Caulobacter spp. have been commonly attributed an aquatic and oligotrophic lifestyle yet are not uncommon in nutrient-rich or soil environments. This study evaluates the environmental and ecological associations of Caulobacter to reconcile past evidence, largely limited to culturing and microscopy, with currently available metagenomic and genomic data. The distribution of Caulobacter species and their characteristic adhesion-conferring genes, holdfast (hfaAB), were determined using collections of 10,641 16S rRNA gene libraries (196 studies) and 2625 shotgun metagenomes (190 studies) from a range of terrestrial and aquatic environments. Evidence for ecotypic variation was tested in 26 genomes sourced from soil, rhizosphere, plant, groundwater, and water. Caulobacter were, on average, fourfold more relatively abundant in soil than in aquatic environments, and abundant in decomposing wood, compost, and particulate matter (in air and water). Caulobacter holdfast genes were 35-fold more abundant in soils than aquatic environments. Ecotypic differences between soil and aquatic Caulobacter were evident in the environmental associations of several species and differences in genome size and content among isolates. However, most abundant species were common to both environments, suggesting populations exist in a continuum that was evident in the re-analysis of studies on the temporal dynamics of, and sources of bacterioplankton to, lakes and rivers. This study provides a new perspective on the ecological profile of Caulobacter, demonstrating that members of this genus are predominantly soil-borne, possess an overlooked role in plant matter decomposition and a dependency on water-mediated dispersal.
Association study and mutation sequencing of genes on chromosome 15q11-q13 identified GABRG3 as a susceptibility gene for autism in Chinese Han population
Authors: Wang Linyan , Li Jun , Shuang Mei , Lu Tianlan , Wang Ziqi , Zhang Tian , Yue Weihua , Jia Meixiang , Ruan Yanyan , Liu Jing , Wu Zhiliu , Zhang Dai , Wang Lifang
Published: August 2018

Cytogenetic studies suggested that chromosome 15q11-q13 might be a candidate region that increases the risk of autism. Previous association studies in Caucasian populations identified the risk variants of genes in this region. However, the association of these genes with autism in Chinese Han population remains unclear. Herein, 512 autism trios were utilized for a family-based association study of 41 tag single nucleotide polymorphisms (SNPs) in this region to explore the association between protein-coding genes on chromosome 15q11-q13 and autism in Chinese Han population. Furthermore, we sequenced these autism-related genes to detect rare variants in 512 autism trios and 575 healthy controls. Our results showed that the C allele of rs7180500 inGABRG3was a risk variant for autism (p = 0.00057). The expression quantitative trait loci (eQTL) analysis revealed that the C allele of rs7180500 might be associated with the expression ofGABRG3in the cerebellum (Braineac:p = 0.0048; GTEx:p = 0.0010). Moreover, the sequencing identified two rare variants rs201602655 (p.Val233Met) and rs201427468 (p.Pro365Ser) inGABRG3and six rare variants inGABRB3in autistic patients. Among these variants, rs201602655 (p.Val233Met) inGABRG3were observed in 9 of 512 autistic children and 2 of 575 healthy controls (Pearsonχ2-test,χ2 = 5.375,p = 0.020). The functional prediction indicated that rs201602655 (p.Val233Met) might be deleterious. Thus, these findings demonstrated thatGABRG3might contribute to the pathogenesis of autism in Chinese Han population.
Absent sleep EEG spindle activity in GluA1 (Gria1) knockout mice: relevance to neuropsychiatric disorders
Authors: Ang Gauri , McKillop Laura E. , Purple Ross , Blanco-Duque Cristina , Peirson Stuart N. , Foster Russell G. , Harrison Paul J. , Sprengel Rolf , Davies Kay E. , Oliver Peter L. , Bannerman David M. , Vyazovskiy Vladyslav V.
Published: August 2018

Sleep EEG spindles have been implicated in attention, sensory processing, synaptic plasticity and memory consolidation. In humans, deficits in sleep spindles have been reported in a wide range of neurological and psychiatric disorders, including schizophrenia. Genome-wide association studies have suggested a link between schizophrenia and genes associated with synaptic plasticity, including the Gria1 gene which codes for the GluA1 subunit of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor. Gria1−/− mice exhibit a phenotype relevant for neuropsychiatric disorders, including reduced synaptic plasticity and, at the behavioural level, attentional deficits leading to aberrant salience. In this study we report a striking reduction of EEG power density including the spindle-frequency range (10–15 Hz) during sleep in Gria1−/− mice. The reduction of spindle-activity in Gria1−/− mice was accompanied by longer REM sleep episodes, increased EEG slow-wave activity in the occipital derivation during baseline sleep, and a reduced rate of decline of EEG slow wave activity (0.5–4 Hz) during NREM sleep after sleep deprivation. These data provide a novel link between glutamatergic dysfunction and sleep abnormalities in a schizophrenia-relevant mouse model.
Direct observation of room-temperature out-of-plane ferroelectricity and tunneling electroresistance at the two-dimensional limit
Authors: Wang H. , Liu Z. R. , Yoong H. Y. , Paudel T. R. , Xiao J. X. , Guo R. , Lin W. N. , Yang P. , Wang J. , Chow G. M. , Venkatesan T. , Tsymbal E. Y. , Tian H. , Chen J. S.
Published: August 2018

Out-of-plane ferroelectricity with a high transition temperature in nanometer-scale films is required to miniaturize electronic devices. Direct visualization of stable ferroelectric polarization and its switching behavior in atomically thick films is critical for achieving this goal. Here, ferroelectric order at room temperature in the two-dimensional limit is demonstrated in tetragonal BiFeO3 ultrathin films. Using aberration-corrected scanning transmission electron microscopy, we directly observed robust out-of-plane spontaneous polarization in one-unit-cell-thick BiFeO3 films. High-resolution piezoresponse force microscopy measurements show that the polarization is stable and switchable, whereas a tunneling electroresistance effect of up to 370% is achieved in BiFeO3 films. Based on first-principles calculations and Kelvin probe force microscopy measurements, we explain the mechanism of polarization stabilization by the ionic displacements in oxide electrode and the surface charges. Our results indicate that critical thickness for ferroelectricity in the BiFeO3 film is virtually absent, making it a promising candidate for high-density nonvolatile memories.
Layer specific observation of slow thermal equilibration in ultrathin metallic nanostructures by femtosecond X-ray diffraction
Authors: Pudell J. , Maznev A. A. , Herzog M. , Kronseder M. , Back C. H. , Malinowski G. , von Reppert A. , Bargheer M.
Published: August 2018

Ultrafast heat transport in nanoscale metal multilayers is of great interest in the context of optically induced demagnetization, remagnetization and switching. If the penetration depth of light exceeds the bilayer thickness, layer-specific information is unavailable from optical probes. Femtosecond diffraction experiments provide unique experimental access to heat transport over single digit nanometer distances. Here, we investigate the structural response and the energy flow in the ultrathin double-layer system: gold on ferromagnetic nickel. Even though the excitation pulse is incident from the Au side, we observe a very rapid heating of the Ni lattice, whereas the Au lattice initially remains cold. The subsequent heat transfer from Ni to the Au lattice is found to be two orders of magnitude slower than predicted by the conventional heat equation and much slower than electron–phonon coupling times in Au. We present a simplified model calculation highlighting the relevant thermophysical quantities.
Deficient humoral responses and disrupted B-cell immunity are associated with fatal SFTSV infection
Authors: Song Peixin , Zheng Nan , Liu Yong , Tian Chen , Wu Xilin , Ma Xiaohua , Chen Deyan , Zou Xue , Wang Guiyang , Wang Huanru , Zhang Yongyang , Lu Sufang , Wu Chao , Wu Zhiwei
Published: August 2018

Severe Fever with Thrombocytopenia Syndrome (SFTS), an emerging infectious disease caused by a novel phlebovirus, is associated with high fatality. Therapeutic interventions are lacking and disease pathogenesis is yet to be fully elucidated. The anti-viral immune response has been reported, but humoral involvement in viral pathogenesis is poorly understood. Here we show defective serological responses to SFTSV is associated with disease fatality and a combination of B-cell and T-cell impairment contribute to disruption of anti-viral immunity. The serological profile in deceased patients is characterized by absence of specific IgG to viral nucleocapsid and glycoprotein due to failure of B-cell class switching. Expansion and impairment of antibody secretion is a signature of fatal SFTSV infection. Apoptosis of monocytes in the early stage of infection diminishes antigen-presentation by dendritic cells, impedes differentiation and function of T follicular helper cells, and contributes to failure of the virus-specific humoral response.
Single-cell analysis reveals that stochasticity and paracrine signaling control interferon-alpha production by plasmacytoid dendritic cells
Authors: Wimmers Florian , Subedi Nikita , van Buuringen Nicole , Heister Daan , Vivié Judith , Beeren-Reinieren Inge , Woestenenk Rob , Dolstra Harry , Piruska Aigars , Jacobs Joannes F. M. , van Oudenaarden Alexander , Figdor Carl G. , Huck Wilhelm T. S. , de Vries I. Jolanda M. , Tel Jurjen
Published: August 2018

Type I interferon (IFN) is a key driver of immunity to infections and cancer. Plasmacytoid dendritic cells (pDCs) are uniquely equipped to produce large quantities of type I IFN but the mechanisms that control this process are poorly understood. Here we report on a droplet-based microfluidic platform to investigate type I IFN production in human pDCs at the single-cell level. We show that type I IFN but not TNFα production is limited to a small subpopulation of individually stimulated pDCs and controlled by stochastic gene regulation. Combining single-cell cytokine analysis with single-cell RNA-seq profiling reveals no evidence for a pre-existing subset of type I IFN-producing pDCs. By modulating the droplet microenvironment, we demonstrate that vigorous pDC population responses are driven by a type I IFN amplification loop. Our study highlights the significance of stochastic gene regulation and suggests strategies to dissect the characteristics of immune responses at the single-cell level.
BCL11A interacts with SOX2 to control the expression of epigenetic regulators in lung squamous carcinoma
Authors: Lazarus Kyren A. , Hadi Fazal , Zambon Elisabetta , Bach Karsten , Santolla Maria-Francesca , Watson Julie K. , Correia Lucia L. , Das Madhumita , Ugur Rosemary , Pensa Sara , Becker Lukas , Campos Lia S. , Ladds Graham , Liu Pentao , Evan Gerard I. , McCaughan Frank M. , Le Quesne John , Lee Joo-Hyeon , Calado Dinis , Khaled Walid T.
Published: August 2018

Patients diagnosed with lung squamous cell carcinoma (LUSC) have limited targeted therapies. We report here the identification and characterisation of BCL11A, as a LUSC oncogene. Analysis of cancer genomics datasets revealed BCL11A to be upregulated in LUSC but not in lung adenocarcinoma (LUAD). Experimentally we demonstrate that non-physiological levels of BCL11A in vitro and in vivo promote squamous-like phenotypes, while its knockdown abolishes xenograft tumour formation. At the molecular level we found that BCL11A is transcriptionally regulated by SOX2 and is required for its oncogenic functions. Furthermore, we show that BCL11A and SOX2 regulate the expression of several transcription factors, including SETD8. We demonstrate that shRNA-mediated or pharmacological inhibition of SETD8 selectively inhibits LUSC growth. Collectively, our study indicates that BCL11A is integral to LUSC pathology and highlights the disruption of the BCL11A–SOX2 transcriptional programme as a novel candidate for drug development.
Room-temperature mechanocaloric effects in lithium-based superionic materials
Authors: Sagotra Arun K. , Chu Dewei , Cazorla Claudio
Published: August 2018

Mechanocaloric materials undergo sizable temperature changes during stress-induced phase transformations and hence are highly sought after for solid-state cooling applications. Most known mechanocaloric materials, however, operate at non-ambient temperatures and involve first-order structural transitions that pose practical cyclability issues. Here, we demonstrate large room-temperature mechanocaloric effects in the absence of any structural phase transformation in the fast-ion conductor Li3N (|ΔS| ~ 25 J K−1 kg−1 and |ΔT| ~ 5 K). Depending on whether the applied stress is hydrostatic or uniaxial the resulting caloric effect is either direct (ΔT > 0) or inverse (ΔT < 0). The dual caloric response of Li3N is due exclusively to stress-induced variations on its ionic conductivity, which entail large entropy and volume changes that are fully reversible. Our work should motivate the search of large and dual mechanocaloric effects in a wide variety of superionic materials already employed in electrochemical devices.
LTR retrotransposons transcribed in oocytes drive species-specific and heritable changes in DNA methylation
Authors: Brind’Amour Julie , Kobayashi Hisato , Richard Albert Julien , Shirane Kenjiro , Sakashita Akihiko , Kamio Asuka , Bogutz Aaron , Koike Tasuku , Karimi Mohammad M. , Lefebvre Louis , Kono Tomohiro , Lorincz Matthew C.
Published: August 2018

De novo DNA methylation (DNAme) during mouse oogenesis occurs within transcribed regions enriched for H3K36me3. As many oocyte transcripts originate in long terminal repeats (LTRs), which are heterogeneous even between closely related mammals, we examined whether species-specific LTR-initiated transcription units (LITs) shape the oocyte methylome. Here we identify thousands of syntenic regions in mouse, rat, and human that show divergent DNAme associated with private LITs, many of which initiate in lineage-specific LTR retrotransposons. Furthermore, CpG island (CGI) promoters methylated in mouse and/or rat, but not human oocytes, are embedded within rodent-specific LITs and vice versa. Notably, at a subset of such CGI promoters, DNAme persists on the maternal genome in fertilized and parthenogenetic mouse blastocysts or in human placenta, indicative of species-specific epigenetic inheritance. Polymorphic LITs are also responsible for disparate DNAme at promoter CGIs in distantly related mouse strains, revealing that LITs also promote intra-species divergence in CGI DNAme.
Epigenetic regulation of the circadian gene Per1 contributes to age-related changes in hippocampal memory
Authors: Kwapis Janine L. , Alaghband Yasaman , Kramár Enikö A. , López Alberto J. , Vogel Ciernia Annie , White André O. , Shu Guanhua , Rhee Diane , Michael Christina M. , Montellier Emilie , Liu Yu , Magnan Christophe N. , Chen Siwei , Sassone-Corsi Paolo , Baldi Pierre , Matheos Dina P. , Wood Marcelo A.
Published: August 2018

Aging is accompanied by impairments in both circadian rhythmicity and long-term memory. Although it is clear that memory performance is affected by circadian cycling, it is unknown whether age-related disruption of the circadian clock causes impaired hippocampal memory. Here, we show that the repressive histone deacetylase HDAC3 restricts long-term memory, synaptic plasticity, and experience-induced expression of the circadian genePer1in the aging hippocampus without affecting rhythmic circadian activity patterns. We also demonstrate that hippocampalPer1is critical for long-term memory formation. Together, our data challenge the traditional idea that alterations in the core circadian clock drive circadian-related changes in memory formation and instead argue for a more autonomous role for circadian clock gene function in hippocampal cells to gate the likelihood of long-term memory formation.
Unraveling exciton–phonon coupling in individual FAPbI3 nanocrystals emitting near-infrared single photons
Authors: Fu Ming , Tamarat Philippe , Trebbia Jean-Baptiste , Bodnarchuk Maryna I. , Kovalenko Maksym V. , Even Jacky , Lounis Brahim
Published: August 2018

Formamidinium lead iodide (FAPbI3) exhibits the narrowest bandgap energy among lead halide perovskites, thus playing a pivotal role for the development of photovoltaics and near-infrared classical or quantum light sources. Here, we unveil the fundamental properties of FAPbI3 by spectroscopic investigations of nanocrystals of this material at the single-particle level. We show that these nanocrystals deliver near-infrared single photons suitable for quantum communication. Moreover, the low temperature photoluminescence spectra of FAPbI3 nanocrystals reveal the optical phonon modes responsible for the emission line broadening with temperature and a vanishing exciton–acoustic phonon interaction in these soft materials. The photoluminescence decays are governed by thermal mixing between fine structure states, with a two-optical phonon Raman scattering process. These results point to a strong Frölich interaction and to a phonon glass character that weakens the interactions of charge carriers with acoustic phonons and thus impacts their relaxation and mobility in these perovskites.
Photon antibunching control in a quantum dot and metallic nanoparticle hybrid system with non-Markovian dynamics
Authors: Moradi T. , Harouni M. Bagheri , Naderi M. H.
Published: August 2018

Photon-number statistics of the emitted photons from a quantum dot placed in the vicinity of a metallic nanoparticle driven by a laser in the non-Markovian regime is investigated theoretically. In the model scheme, the quantum dot is considered as an InAs three-level system in L-type configuration with two transition channels. We aim to introduce the hybrid system as a nonclassical photon source and control the antibunching behavior of the emitted photons by the geometrical as well as the physical parameters of the hybrid system. Our approach is based on the classical Green’s function technique and time convolution master equation. The results reveal that the emitted photons from the hybrid system under consideration are antibunched and energy is exchanged between the QD and nanoshell. By increasing the QD-MNP separation distance, the detuning frequency between the QD transitions and surface plasmon modes, and the Rabi frequency the antibunching time increases while the backaction of the reservoir on the QD decreases. To sum up, we conclude that the studied system has the potential to be a highly controllable single-photon source.
Screening for diabetes with HbA1c: Test performance of HbA1c compared to fasting plasma glucose among Chinese, Malay and Indian community residents in Singapore
Authors: Lim Wei-Yen , Ma Stefan , Heng Derrick , Tai E. Shyong , Khoo Chin Meng , Loh Tze Ping
Published: August 2018

The prevalence of diabetes in Singapore is high. Screening to facilitate early detection and intervention has been shown to be cost-effective. Current clinical practice guidelines in Singapore recommend screening with fasting plasma glucose (FPG), followed by an oral glucose tolerance test (OGTT) in those with FPG 6.1-6.9 mmol/L. Glycated haemoglobin A1c (HbA1c) has robust stability at ambient temperature, and can be performed on non-fasted capillary blood samples, making it an attractive potential alternative for screening. However, limitations of HbA1c include differential performance in different races, and its performance as a screening test has not been well characterized in Asian populations. This study compares HbA1c and FPG as diabetes screening modalities in 3540 community-dwelling Singapore residents of Chinese, Malay and Indian race to detect diabetes mellitus diagnosed based on blood glucose (FPG ≥ 7.0 mmol/L, 2 hr OGTT ≥ 11.1 mmol/L). The area under the receiver-operating-characteristic curve (AUC) was higher for FPG compared to HbA1c in the overall population and age, race and age-race strata, but these differences were not statistically significant. HbA1c > = 7.0% identified 95% of individuals with diabetes mellitus, and the remainder had impaired glucose tolerance (IGT). HbA1c cut-off at 6.1% had better sensitivity (0.825) to FPG at 6.1 mmol/L. The positive predictive value of HbA1c at 6.1% was 40–50% in different age-race combinations with a negative predictive value of about 98%. If follow-up screening with FPG is used, a lower cut-off at 5.6 mmol/L is appropriate in identifying people with pre-diabetes, as about 85% of people with HbA1c 6.1–6.9% and FPG 5.6–6.9 mmol/L had IFG/IGT or diabetes in the study sample. HbA1c is an appropriate alternative to FPG as a first-step screening test, and the combination of Hba1c > = 6.1% and FPG > = 5.6 mmol/L would improve the identification of individuals with diabetes mellitus and prediabetes.
An Intermediate Incubation Period and Primitive Brooding in a Theropod Dinosaur
Authors: Varricchio David J. , Kundrát Martin , Hogan Jason
Published: August 2018

Non-avian dinosaurs such as oviraptorosaurs and troodontids share several important reproductive characters with modern birds, including eggshell microstructure and iterative egg production. Nevertheless, debate exists concerning their incubation strategies. Here we estimate incubation period for the troodontid,Troodon formosus, by examining a near-term embryonic tooth. Synchrotron scanning and histologic thin sections allowed counting of daily (von Ebner) growth lines. The tooth preserves 31 intact lines with an average spacing of 3.3 ± 0.96 μm. Adding 8 more for the missing crown tip gives a total age of 39 days. Modern crocodilians begin to establish their functional dentition at approximately 47% through incubation. Thus, this tooth age suggests aTroodonincubation period of 74 days, falling midway between avian (44.4 days) and reptilian (107.3 days) values predicted by theTroodonegg mass (314 g). An accelerated incubation relative to modern reptiles supports brooding and concurs with a suite of features in oviraptorosaurs and troodontids (sequential laying, large complex clutches, and precocial young) that appear dependent upon both adult body and incubation temperatures elevated over ambient conditions. However, the largely buried condition ofTroodonclutches may have prohibited efficient brooding, necessitating longer incubation than that of modern birds with fully exposed eggs.
Spinal arthritis in cane toads across the Australian landscape
Authors: Bower Deborah S. , Yasumiba Kiyomi , Trumbo Daryl R. , Alford Ross A. , Schwarzkopf Lin
Published: August 2018

Loss of fitness can be a consequence of selection for rapid dispersal ability in invasive species. Increased prevalence of spinal arthritis may occur in cane toad populations at the invasion front as a cost of increased invasiveness, but our knowledge of the ecological drivers of this condition is lacking. We aimed to determine the factors explaining the prevalence of spinal arthritis in populations across the Australian landscape. We studied populations across a gradient of invasion histories. We collected 2415 toads over five years and determined the presence and size of spondylosis for each individual. We examined the effect of host size, leg length and invasion history on the prevalence of spondylosis. Host size was a significant predictor of spondylosis across populations. Contrary to our expectation, the overall prevalence of spondylosis was not positively related to invasion history and did not correlate with toad relative leg length. Rather than invasion age, the latitude at which populations were sampled provided an alternate explanation for the prevalence of spondylosis in cane toad populations and suggested that the incidence of this condition did not increase as a physiological cost of invasion, but is instead related to physical variables, such as climate.