bluuebunny/crossref_metadata_2025 huggingface dataset:
Cramer’s rules for the system of quaternion matrix equations withη-Hermicity
Authors: Kyrchei Ivan I.
Published: July 2019

The system of two-sided quaternion matrix equations withη-Hermicity,A1XA1η*=C1,A2XA2η*=C2is considered in the paper. Using noncommutative row-column determinants previously introduced by the author, determinantal representations (analogs of Cramer’s rule) of a general solution to the system are obtained. As special cases, Cramer’s rules for anη-Hermitian solution whenC1=Cη*1andC2=Cη*2and for anη-skew-Hermitian solution whenC1= −Cη*1andC2= −Cη*2are also explored.
Attitudes thérapeutiques dans les cas de fermeture des espaces d’agénésie d’incisives latérales maxillaires chez l’enfant et l’adolescent
Authors: Le Gall Michel , Bachet Christophe , Chevalier Emilie , Dameron Cyril , Philip-Alliez Camille
Published: July 2019

L’absence d’incisives latérales maxillaires est à l’origine de problèmes esthétiques, occlusaux et fonctionnels majeurs compte tenu de la position stratégique de celles-ci dans le sourire.

Les options thérapeutiques proposées sont l’abstention thérapeutique, la réouverture d’espaces et le remplacement prothétique, et la fermeture d’espaces par mésialisation des dents de l’arcade.

Cet article est centré sur la fermeture des espaces d’agénésies et propose différentes solutions thérapeutiques.
La gestion osseuse des sites d’agénésie d’incisives latérales
Authors: Limbour Patrick , Murden Krisnen , Le Hebel François , Clipet Fabrice
Published: July 2019

Le recours à l’implantologie orale est une solution avérée dans le cadre des reconstructions d’agénésie des incisives latérales. Pour autant, l’obtention d’un résultat esthétique probant nécessite une connaissance actualisée des phénomènes de croissance osseuse, ainsi qu’une maîtrise des aménagements osseux et muqueux, souvent nécessaire à l’obtention d’un environnement implantaire optimal face aux carences anatomiques des sites agénésiques.
Mikrobiom & NASH – enge Komplizen in der Progression von Fettlebererkrankungen
Authors: Wree Alexander , Geisler Lukas Jonathan , Tacke Frank
Published: July 2019

Einhergehend mit der steigenden Prävalenz von Übergewicht, metabolischem Syndrom und Typ-2-Diabetes nehmen nicht-alkoholische Fettlebererkrankungen (NAFLD) stark zu und stellen eine große Herausforderung in der Gastroenterologie dar. Viele Studien konnten nachweisen, dass das Mikrobiom in einem engen Zusammenhang mit der Progression von ernährungsbedingten Krankheitsbildern, insbesondere auch von Fettlebererkrankungen, steht. Veränderungen in der Quantität und Qualität der Darmflora, allgemein als Dysbiose bezeichnet, bedingen veränderte Metabolisierung von Nahrungsmitteln, erhöhte Permeabilität der Darmbarriere („leaky gut“) und konsekutiv Entzündungsprozesse in der Leber. Dies begünstigt sowohl das Fortschreiten von Adipositas und metabolischen Störungen als auch von NAFLD zur nicht-alkoholischen Steatohepatitis (NASH), hepatischen Fibrose, Leberzirrhose und hepatozellulärem Karzinom (HCC). Wichtige molekulare Mechanismen beinhalten mikrobielle Stoffwechselprodukte, mikrobielle und endogene Signalstoffe (sogenannte PAMPs/DAMPs) sowie Gallensäuren. Essenzielle zelluläre Mechanismen umfassen immunologische Zellen in Darm und Leber, insbesondere Makrophagen und Kupffer-Zellen, sowie Darmepithelzellen und Hepatozyten als zentrale Regulatoren des Stoffwechsels. In dieser Übersicht wollen wir anhand aktueller wissenschaftlicher Arbeiten und klinischer Studien kurz auf die relevanten Spezies des humanen Mikrobioms eingehen, die mikrobielle Analytik erläutern, die wichtigsten molekularen Zusammenhänge zwischen Mikrobiom und NAFLD/NASH erklären und schlussendlich Möglichkeiten der Mikrobiom-modulierenden Therapie zur Behandlung von Fettlebererkrankungen darlegen.
Mikrobielle Einflüsse in der Tumorentwicklung und Tumortherapie
Authors: Zeissig Sebastian
Published: July 2019

Viren und Bakterien spielen eine zentrale Rolle in der Entstehung von Malignomen im Gastrointestinaltrakt. So konnte bereits vor Dekaden eine Assoziation von Helicobacter pylori und dem Magenkarzinom sowie MALT-Lymphomen, und von Hepatitis-B- und C-Virus-Infektionen und dem hepatozellulären Karzinom nachgewiesen werden. Faszinierende Daten der letzten Jahre deuten jedoch einen weit über diese Zusammenhänge hinausgehenden Beitrag mikrobieller Erreger zur Karzinogenese im Gastrointestinaltrakt und der Leber an. So konnte gezeigt werden, dass Barriere-Defekte sowie Veränderungen in der Komposition der intestinalen Mikrobiota die kolorektale und hepatozelluläre Karzinogenese fördern. Darüber hinaus konnte die überraschende Beobachtung gemacht werden, dass die Mikrobiota nicht nur in lokaler Weise die Tumorentwicklung reguliert, sondern auch maßgeblichen Einfluss auf die Wirksamkeit systemischer Tumortherapien hat. Im vorliegenden Artikel sollen aktuelle Daten zur mikrobiellen Regulation der Tumorentstehung und der Beeinflussung systemischer Tumortherapien dargestellt werden und Implikationen für die klinische Diagnostik und Therapie diskutiert werden.
Sleep Hygiene for Optimizing Recovery in Athletes: Review and Recommendations
Authors: Vitale Kenneth C. , Owens Roberts , Hopkins Susan R. , Malhotra Atul
Published: July 2019

For elite athletes who exercise at a high level, sleep is critical to overall health. Many studies have documented the effects of sleep deprivation in the general population, but few studies exist regarding specific effects in the athlete. This review summarizes the effects of sleep deprivation and sleep extension on athletic performance, including reaction time, accuracy, strength and endurance, and cognitive function. There are clear negative effects of sleep deprivation on performance, including reaction time, accuracy, vigor, submaximal strength, and endurance. Cognitive functions such as judgment and decision-making also suffer. Sleep extension can positively affect reaction times, mood, sprint times, tennis serve accuracy, swim turns, kick stroke efficiency, and increased free throw and 3-point accuracy. Banking sleep (sleep extension prior to night of intentional sleep deprivation before sporting event) is a new concept that may also improve performance. For sports medicine providers, the negative effects of sleep deprivation cannot be overstated to athletes. To battle sleep deprivation, athletes may seek supplements with potentially serious side effects; improving sleep quality however is simple and effective, benefiting not only athlete health but also athletic performance.
Silymarin Enriched Extract (Silybum marianum) Additive Effect on Doxorubicin-Mediated Cytotoxicity in PC-3 Prostate Cancer Cells
Authors: Gioti Katerina , Papachristodoulou Anastasia , Benaki Dimitra , Havaki Sophia , Beloukas Apostolos , Vontzalidou Argyro , Aligiannis Nektarios , Skaltsounis Alexios-Leandros , Mikros Emmanuel , Tenta Roxane
Published: July 2019

Silymarin-enriched extract (SEE) is obtained from Silybum marianum (Asteraceae). Doxorubicin (DXR) is a widely used chemotherapeutical yet with severe side effects. The goal of the present study was to assess the pharmacologic effect of SEE and its bioactive components silibinin and silychristine when administrated alone or in combination with DXR in the human prostate cancer cells (PC-3). PC-3 cells were treated with SEE, silibinin (silybins A and B), silychristine, alone, and in combination with DXR, and cell proliferation was assessed by the MTT assay. Cell cycle, apoptosis, and autophagy rate were assessed by flow cytometry. Expression levels of autophagy-related genes were quantified by qRT-PCR, ELISA and western blot while transmission electron microscopy was performed to reveal autophagic structures. Finally, NMR spectrometry was used to identify specific metabolites related to autophagy. SEE inhibited PC-3 cell proliferation in a dose-dependent manner while the co-treatment (DXR-SEE) revealed an additive cytotoxic effect. Cell cycle, apoptosis, and autophagy variations were observed in addition to altered expression levels of autophagy related genes (LC3, p62, NBR1, Beclin1, ULK1, AMBRA1), while several modifications in autophagic structures were identified after DXR-SEE co-treatment. Furthermore, treated cells showed a different metabolic profile, with significant alterations in autophagy-related metabolites such as branched-chain amino acids. In conclusion, the DXR-SEE co-treatment provokes perturbations in the autophagic mechanism of prostate cancer cells (PC-3) compared to DXR treatment alone, causing an excessive cell death. These findings propose the putative use of SEE as an adjuvant cytotoxic agent.
A Novel Skin Closure Device for Total Knee Arthroplasty: Randomized Controlled Trial versus Staples
Authors: Benner Rodney W. , Behrens Jonathan P.
Published: July 2019

Twenty-five patients undergoing simultaneous, bilateral total knee arthroplasty (TKA) were randomized to receive skin closure with Zip device on one knee and staples on the other. Patients' pain and scar appearance were rated from 0 (best) to 10 (worst). Knee arc of motion was measured by a physical therapist. At 2 weeks postoperatively, pain scores were significantly better with the Zip device during device wear (p = 0.03) and during device removal (p = 0.003); arc of motion was significantly better with the Zip device (p = 0.002). At 8 weeks of follow-up, scar appearance was significantly better in the Zip device knee as rated by the patients (1.3 vs. 2.6, p = 0.04), the surgeon (1.9 vs. 3.3, p = 0.0006), and three independent plastic surgeons (3.7 vs. 4.8, p < 0.001). Results of this randomized controlled trial show that skin closure with the Zip device resulted in less pain and better scar appearance and knee arc of motion than with staples.
Parental death during childhood and violent crime in late adolescence to early adulthood: a Swedish national cohort study
Authors: Berg Lisa , Rostila Mikael , Arat Arzu , Hjern Anders
Published: July 2019

Childhood parental death has been associated with adverse health, social and educational outcomes. Studies on long-term outcomes are in general scarce and there is little evidence on the long-term impact on anti-social behaviour. This study takes advantage of high-quality register data to investigate risk of violent crime in relation to childhood parental death in a large national cohort covering the entire Swedish population born in 1983–1993 (n = 1,103,656). The impact of parental death from external (suicides, accidents, homicides) and natural causes on risk for violent crime from age 15 to 20–30 years, considering multiple aspects of the rearing environment (including parental psychiatric disorders and criminal offending), was estimated through Cox regression. Unadjusted hazard ratios associated with parental death from external causes ranged between 2.20 and 3.49. For maternal and paternal death from external causes, adjusted hazard ratios were 1.26 (95% confidence intervals: 1.04–1.51) and 1.44 (95% confidence intervals: 1.32–1.57) for men, and 1.47 (95% confidence intervals: 1.05–2.06) and 1.51 (95% confidence intervals: 1.27–1.78) for women. With the exception of maternal death among women (hazard ratio 1.26, 95% confidence intervals: 1.03–1.53), parental death from natural causes was not associated with increased risks in adjusted models. The results underscore the importance of preventive interventions to prevent negative life-course trajectories, particularly when death is sudden and clustered with other childhood adversities.
Surface acoustic wave modes in two-dimensional shallow void inclusion phononic crystals on GaAs
Authors: Muzar Edward , Stotz James A. H.
Published: July 2019

The possibility to control supersonic acoustic wave propagation is intriguing, but when modeling phononic crystal devices, supersonic surface acoustic waves are mired by radiative attenuation and, hence, eschewed in many device designs. In this paper, we study supersonic surface acoustic wave modes in shallow hole phononic crystals computationally with respect to the three bulk wave sound barriers of cubic (001) GaAs. From a first principles modeling approach of linear elasticity, the finite element method, and with the aid of characterization parameters for systematic modal categorization, detailed nuances are observed for supersonic surface waves propagating along the [110]-direction of GaAs with a periodically patterned surface. Modes of interest are distinguished by possessing both strain energy and squared polarization ratios above defined thresholds. The square array of shallow inclusions imparts a metamaterial surface layer effect that results in marked changes in the dispersion, the bulk wave hybridization, and the modal interactions of the surface modes in the Γ-X direction of the phononic crystal, which are characterized by their modal profiles and attenuation via bulk wave radiation. From these findings, we propose an extended sound cone concept to accommodate supersonic surface acoustic waves with low attenuation. Furthermore, at frequencies above the shear vertical bulk dispersion line, well-bounded surface acoustic wave modes are revealed, and the phenomenon of these supersonic modes with limited bulk wave coupling is explored. From these detailed band structures, the systematic method of mode characterization reveals deeper insights into modes that exist in shallow phononic crystals on cubic GaAs.
Antenna-coupled spintronic terahertz emitters driven by a 1550 nm femtosecond laser oscillator
Authors: Nandi U. , Abdelaziz M. S. , Jaiswal S. , Jakob G. , Gueckstock O. , Rouzegar S. M. , Seifert T. S. , Kläui M. , Kampfrath T. , Preu S.
Published: July 2019

We demonstrate antenna-coupled spintronic terahertz (THz) emitters excited by 1550 nm, 90 fs laser pulses. Antennas are employed to optimize THz outcoupling and frequency coverage of ferromagnetic/nonmagnetic metallic spintronic structures. We directly compare the antenna-coupled devices to those without antennas. Using a 200 μm H-dipole antenna and an ErAs:InGaAs photoconductive receiver, we obtain a 2.42-fold larger THz peak-peak signal, a bandwidth of 4.5 THz, and an increase in the peak dynamic range (DNR) from 53 dB to 65 dB. A 25 μm slotline antenna offered 5 dB larger peak DNR and a bandwidth of 5 THz. For all measurements, we use a comparatively low laser power of 45 mW from a commercial fiber-coupled system that is frequently employed in table-top THz time-domain systems.
Dual-frequency piezoelectric micromachined ultrasonic transducers
Authors: Wu Lixiang , Chen Xuyuan , Wang Gaofeng , Zhou Qifa
Published: July 2019

A piezoelectric micromachined ultrasonic transducer (pMUT) operating at dual frequencies (3.75 MHz and 18 MHz) was designed to achieve an ultrasound-on-a-chip solution for next-generation biomedical applications. Optimal electrode configurations for the dual-frequency pMUT were analyzed using finite element methods. It was found that a configuration with two ring electrodes enabled dual-frequency actuations of the diaphragm of the pMUT. Simulations showed that the first two resonances of the diaphragm can be tuned independently, especially with regard to amplitude, by optimizing electrode parameters (e.g., position and dimension) and applied voltage. It was also found that optimized distribution of the R and Z components of the displacement field contributes to near ideal mode superposition in a single diaphragm. Simulations for dual-actuations with both inner and outer ring electrodes showed that the two resonant modes are superimposed without significant vibrational crosstalk and result in high-quality dual-frequency acoustic radiation in water. Unlike transducers using two or more single-frequency ultrasonic resonators to generate dual-frequency ultrasound, every element of dual-frequency pMUTs exhibits dual-resonant response simultaneously.
Key signal contributions in photothermal deflection spectroscopy
Authors: Dickmann Walter , Dickmann Johannes , Bruns Florian Feilong , Kroker Stefanie
Published: July 2019

We report on key signal contributions in photothermal deflection spectroscopy (PDS) of semiconductors at photon energies below the bandgap energy and show how to extract the actual absorption properties from the measurement data. To this end, we establish a rigorous computation scheme for the deflection signal including semianalytic ray tracing to analyze the underlying physical effects. The computation takes into account linear and nonlinear absorption processes affecting the refractive index, thus leading to a deflection of the probe beam. We find that besides the linear mirage effect, nonlinear absorption mechanisms make a substantial contribution to the signal for strongly focused pump beams and sample materials with high two-photon absorption coefficients. For example, the measured quadratic absorption contribution exceeds 5% at a pump beam intensity of about 1.3×105W/cm2 in Si and at 5×104W/cm2 in GaAs. In addition, our method also includes thermal expansion effects as well as spatial gradients of the attenuation properties. We demonstrate that these effects result in an additional deflection contribution that substantially depends on the distance of the photodetector from the readout point. This distance dependent contribution enhances the surface related PDS signal up to two orders of magnitude and may be misinterpreted as surface absorption if not corrected in the analysis of the measurement data. We verify these findings by PDS measurements on crystalline silicon at a wavelength of 1550 nm and provide guidelines on how to extract the actual attenuation coefficient from the PDS signal.
Cavity collapse in highly heterogeneous granular mixtures with different grain size and porosity
Authors: Navarro Pedro Franco , Chiu Po-Hsun , Benson David J. , Higgins Andrew J. , Nesterenko Vitali F.
Published: July 2019

The paper presents results of experimental and numerical research on the mechanism of macrocavity collapse in highly heterogeneous, porous mixtures of Al and W particles with large differences in strength, ductility, and density of components. Mixtures with different grain sizes of W particles and porosity were investigated in plane-strain, high-strain-rate conditions using the explosively driven thick-walled cylinder method. It was demonstrated that macroscopic axial symmetry was preserved, and a pattern of localized shear bands was not formed, which was typical for many previously investigated brittle and ductile materials. The grain size has an influence on the size of the inner cavity microscale instabilities that are formed by the flow of plastically deformed softer Al particles between W particles. Initial porosity did not significantly influence the macrocavity collapse in the investigated materials.
Activated quantum diffusion in a periodic potential above the crossover temperature
Authors: Ianconescu Reuven , Pollak Eli
Published: July 2019

The recently improved Pollak, Grabert, and Hänggi (PGH) turnover theory for activated surface diffusion, including finite barrier effects, is extended and studied in the quantum domain. Analytic expressions are presented for the diffusion coefficient, escape rate, hopping distribution, and mean squared path length of particles initially trapped in one of the wells of a periodic potential, moving under the influence of a frictional and Gaussian random force. Tunneling is included by assuming incoherent quantum hopping at temperatures which are above the crossover temperature between deep tunneling and thermal activation. In the improved version of PGH theory as applied to activated surface diffusion, the potential governing the motion of the unstable mode remains periodic but with a scaled mass which increases with the friction strength. Application of the theory to a periodic cosine potential demonstrates that in the weak damping regime quantum diffusion is slower than classical diffusion due to above barrier quantum reflection which significantly shortens the mean squared path length as compared to the classical result. Finite barrier corrections increase this quantum suppression of diffusion or, equivalently, the inverse isotope effect, whereby the diffusion is faster for a heavier mass.
Bipolar plasticity of the synapse transistors based on IGZO channel with HfOxNy/HfO2/HfOxNy sandwich gate dielectrics
Authors: Yang Wei , Jiang Ran
Published: July 2019

Bipolar plasticity for synaptic emulation of indium gallium zinc oxide thin-film transistors (TFTs) with HfOxNy–HfO2–HfOxNy sandwich-stack films as the gate dielectric was investigated. The postsynaptic current increased when a negative pulse train was applied to the gate of TFTs; when a positive pulse was applied, the postsynaptic current was reduced. This result is discussed based on the charge trapping/releasing process with the assistance of ferroelectric behavior of the enwrapped oxygen-deficient-HfO2 layer. The dual response of this synaptic transistor shows promising prospect in the mimicking of biological neurons.
Significantly enhanced dielectric breakdown strength and energy density of multilayer ceramic capacitors with high efficiency by electrodes structure design
Authors: Cai Ziming , Wang Hongxian , Zhao Peiyao , Chen Lingling , Zhu Chaoqiong , Hui Kezhen , Li Longtu , Wang Xiaohui
Published: July 2019

Multilayer ceramic capacitors (MLCCs) are attracting great interest recently, especially in energy-storage applications due to their high volumetric capacitance, high power density, and fast charge-discharge capability. However, the low dielectric breakdown strength of ferroelectric ceramics always leads to a low discharge energy density, which limits their applications in high-voltage energy-storage systems. In this work, a phase-field electromechanical breakdown model is introduced to give a fundamental understanding of the dielectric breakdown behavior of MLCCs and provide a resource-efficient design strategy for the structure of MLCCs to enhance their dielectric breakdown strength and discharge energy density. Three types of margin lengths of 100 μm, 200 μm, and 400 μm are designed and applied on the MLCCs consisting of ten dielectric layers with the single-layer thickness of 11 μm, to confirm and practice our phase-field breakdown model. A large discharge energy density of 7.8 J cm−3 can be achieved under the applied electric field of 790 kV/cm, together with a high efficiency of 88% in a 400 μm-margin-length MLCC.
-bordism: structure results and geometric representatives
Authors: Limonchenko I. Yu. , Panov T. E. , Chernykh G. S.
Published: July 2019

The first part of this survey gives a modernised exposition of the structure of the special unitary bordism ring, by combining the classical geometric methods of Conner–Floyd, Wall, and Stong with the Adams– Novikov spectral sequence and formal group law techniques that emerged after the fundamental 1967 paper of Novikov. In the second part toric topology is used to describe geometric representatives in

-bordism classes, including toric, quasi-toric, and Calabi–Yau manifolds.

Bibliography: 56 titles.
Conway topograph,

-dynamics and two-valued groups
Authors: Buchstaber V. M. , Veselov A. P.
Published: July 2019

Conway’s topographic approach to binary quadratic forms and Markov triples is reviewed from the point of view of the theory of two-valued groups. This leads naturally to a new class of commutative two-valued groups, which we call involutive. It is shown that the two-valued group of Conway’s lax vectors plays a special role in this class. The group

describing the symmetries of the Conway topograph acts by automorphisms of this two-valued group. Binary quadratic forms are interpreted as primitive elements of the Hopf 2-algebra of functions on the Conway group. This fact is used to construct an explicit embedding of the Conway two-valued group into

and thus to introduce a total group ordering on it. The two-valued algebraic involutive groups with symmetric multiplication law are classified, and it is shown that they are all obtained by the coset construction from the addition law on elliptic curves. In particular, this explains the special role of Mordell’s modification of the Markov equation and reveals its connection with two-valued groups in

-theory. The survey concludes with a discussion of the role of two-valued groups and the group

in the context of integrability in multivalued dynamics.

Bibliography: 104 titles.
On the homotopy finiteness of DG categories
Authors: Efimov A. I.
Published: July 2019

This paper gives a short overview of results related to homotopy finiteness of DG categories. A general plan is explained for proving homotopy finiteness of derived categories of coherent sheaves and coherent matrix factorizations on separated schemes of finite type over a field of characteristic zero.

Bibliography: 39 titles.
Some properties of embeddings of rearrangement invariant spaces
Authors: Astashkin S. V. , Semenov E. M.
Published: July 2019

Let

and

be rearrangement invariant spaces on

, and let

. This embedding is said to be strict if the functions in the unit ball of the space

have absolutely equicontinuous norms in

. For the main classes of rearrangement invariant spaces necessary and sufficient conditions are obtained for an embedding to be strict, and also the relationships this concept has with other properties of embeddings are studied, especially the property of disjoint strict singularity. In the final part of the paper, a characterization of the property of strict embedding in terms of interpolation spaces is obtained.

Bibliography: 23 titles.
Harmonic analysis of functions in homogeneous spaces and harmonic distributions that are periodic or almost periodic at infinity
Authors: Baskakov A. G. , Strukov V. E. , Strukova I. I.
Published: July 2019

Vector-valued functions in homogeneous spaces and harmonic distributions that are periodic or almost periodic at infinity are investigated. The concept of the Fourier series of a function (distribution), periodic or almost periodic at infinity, with coefficients that are functions (distributions) slowly varying at infinity, is introduced. The properties of the Fourier series are investigated and an analogue of Wiener’s theorem on absolutely convergent Fourier series is obtained for functions periodic at infinity. Special attention is given to criteria ensuring that solutions of differential or difference equations are periodic or almost periodic at infinity. The central results involve theorems on the asymptotic behaviour of a bounded operator semigroup whose generator has no limit points on the imaginary axis. In addition, the concept of an asymptotically finite-dimensional operator semigroup is introduced and a theorem on the structure of such a semigroup is proved.

Bibliography: 39 titles.
Higher colimits, derived functors and homology
Authors: Ivanov S. O. , Mikhailov R. V. , Sosnilo V. A.
Published: July 2019

We develop a theory of higher colimits over categories of free presentations. We show that different homology functors such as Hochschild and cyclic homology of algebras over a field of characteristic zero, simplicial derived functors, and group homology can be obtained as higher colimits of simply defined functors. Connes’ exact sequence linking Hochschild and cyclic homology was obtained using this approach as a corollary of a simple short exact sequence. As an application of the developed theory, we show that the third reduced

-functor can be defined as the colimit of the second reduced

-functor applied to the fibre square of a free presentation of an algebra. We also prove a Hopf-type formula for odd-dimensional cyclic homology of an algebra over a field of characteristic zero.

Bibliography: 17 titles.
The orphan nuclear receptor NR4A3 controls the differentiation of monocyte-derived dendritic cells following microbial stimulation
Authors: Boulet Salix , Daudelin Jean-François , Odagiu Livia , Pelletier Adam-Nicolas , Yun Tae Jin , Lesage Sylvie , Cheong Cheolho , Labrecque Nathalie
Published: July 2019

In response to microbial stimulation, monocytes can differentiate into macrophages or monocyte-derived dendritic cells (MoDCs) but the molecular requirements guiding these possible fates are poorly understood. In addition, the physiological importance of MoDCs in the host cellular and immune responses to microbes remains elusive. Here, we demonstrate that the nuclear orphan receptor NR4A3 is required for the proper differentiation of MoDCs but not for other types of DCs. Indeed, the generation of DC-SIGN
+
MoDCs in response to LPS was severely impaired in
Nr4a3
−/−
mice, which resulted in the inability to mount optimal CD8
+
T cell responses to gram-negative bacteria. Transcriptomic analyses revealed that NR4A3 is required to skew monocyte differentiation toward MoDCs, at the expense of macrophages, and allows the acquisition of migratory characteristics required for MoDC function. Altogether, our data identify that the NR4A3 transcription factor is required to guide the fate of monocytes toward MoDCs.
A SWI/SNF subunit regulates chromosomal dissociation of structural maintenance complex 5 during DNA repair in plant cells
Authors: Jiang Jieming , Mao Ning , Hu Huan , Tang Jiahang , Han Danlu , Liu Song , Wu Qian , Liu Yiyang , Peng Changlian , Lai Jianbin , Yang Chengwei
Published: July 2019

Significance

DNA repair is essential for accurate maintenance of genetic information in all types of cells, but what regulatory mechanisms act on the complexes involved in this process has been unclear. The structural maintenance complex 5/6 (SMC5/6) associates with chromosomes under normal conditions and is recruited to DNA double-strand breaks for repair. However, the mechanism by which this conserved complex becomes dissociated from its original chromosomal location during DNA repair is completely unknown. Here, we describe a mechanism in which the chromosomal dissociation of SMC5 in plant cells is mediated via SWI3B, a subunit of the SWI/SNF complex. Given that these proteins are evolutionarily conserved, the current findings may provide hints for the study of DNA repair in other species.
Active cargo positioning in antiparallel transport networks
Authors: Richard Mathieu , Blanch-Mercader Carles , Ennomani Hajer , Cao Wenxiang , De La Cruz Enrique M. , Joanny Jean-François , Jülicher Frank , Blanchoin Laurent , Martin Pascal
Published: July 2019

Significance

Cellular functions rely on small groups of molecular motors to transport their cargoes throughout the cell along polar filaments of the cytoskeleton. Cytoskeletal filaments self-assemble into dense networks comprising intersections and filaments of mixed polarity, challenging directed motor-based transport. Using micropatterns of actin polymerization in vitro, we investigated stochastic transport of colloidal beads in antiparallel networks of overlapping actin filaments. We found that beads coated with myosin motors sensed the net polarity of the actin network, resulting in active bead positioning to regions of neutral polarity with a precision depending on the motor type. A theoretical description of our experimental results provides the key physical rules for cargo transport and positioning in filament networks of mixed polarity.
Efficient T cell–B cell collaboration guides autoantibody epitope bias and onset of celiac disease
Authors: Iversen Rasmus , Roy Bishnudeo , Stamnaes Jorunn , Høydahl Lene S. , Hnida Kathrin , Neumann Ralf S. , Korponay-Szabó Ilma R. , Lundin Knut E. A. , Sollid Ludvig M.
Published: July 2019

B cells play important roles in autoimmune diseases through autoantibody production, cytokine secretion, or antigen presentation to T cells. In most cases, the contribution of B cells as antigen-presenting cells is not well understood. We have studied the autoantibody response against the enzyme transglutaminase 2 (TG2) in celiac disease patients by generating recombinant antibodies from single gut plasma cells reactive with discrete antigen domains and by undertaking proteomic analysis of anti-TG2 serum antibodies. The majority of the cells recognized epitopes in the N-terminal domain of TG2. Antibodies recognizing C-terminal epitopes interfered with TG2 cross-linking activity, and B cells specific for C-terminal epitopes were inefficient at taking up TG2-gluten complexes for presentation to gluten-specific T cells. The bias toward N-terminal epitopes hence reflects efficient T-B collaboration. Production of antibodies against N-terminal epitopes coincided with clinical onset of disease, suggesting that TG2-reactive B cells with certain epitope specificities could be the main antigen-presenting cells for pathogenic, gluten-specific T cells. The link between B cell epitopes, antigen presentation, and disease onset provides insight into the pathogenic mechanisms of a T cell-mediated autoimmune condition.
How lovebirds maneuver through lateral gusts with minimal visual information
Authors: Quinn Daniel , Kress Daniel , Chang Eric , Stein Andrea , Wegrzynski Michal , Lentink David
Published: July 2019

Flying birds maneuver effectively through lateral gusts, even when gust speeds are as high as flight speeds. What information birds use to sense gusts and how they compensate is largely unknown. We found that lovebirds can maneuver through 45° lateral gusts similarly well in forest-, lake-, and cave-like visual environments. Despite being diurnal and raised in captivity, the birds fly to their goal perch with only a dim point light source as a beacon, showing that they do not need optic flow or a visual horizon to maneuver. To accomplish this feat, lovebirds primarily yaw their bodies into the gust while fixating their head on the goal using neck angles of up to 30°. Our corroborated model for proportional yaw reorientation and speed control shows how lovebirds can compensate for lateral gusts informed by muscle proprioceptive cues from neck twist. The neck muscles not only stabilize the lovebirds’ visual and inertial head orientations by compensating low-frequency body maneuvers, but also attenuate faster 3D wingbeat-induced perturbations. This head stabilization enables the vestibular system to sense the direction of gravity. Apparently, the visual horizon can be replaced by a gravitational horizon to inform the observed horizontal gust compensation maneuvers in the dark. Our scaling analysis shows how this minimal sensorimotor solution scales favorably for bigger birds, offering local wind angle feedback within a wingbeat. The way lovebirds glean wind orientation may thus inform minimal control algorithms that enable aerial robots to maneuver in similar windy and dark environments.
Adaptation by naïve CD4
+
T cells to self-antigen–dependent TCR signaling induces functional heterogeneity and tolerance
Authors: Zinzow-Kramer Wendy M. , Weiss Arthur , Au-Yeung Byron B.
Published: July 2019

Significance

Prior to their exposure to foreign antigens, naïve T cells experience weak T cell antigen receptor (TCR) signals induced by self-antigens. These “basal” TCR signals vary in strength, which is reflected by the relative expression of markers such as CD5, Ly6C, and Nur77-GFP. Using a combination of Nur77-GFP and Ly6C, we show that the range of basal TCR signaling is broader than previously thought. A population of cells at the high end of this range experiences relatively strong basal TCR signals and attenuated responses to foreign antigen stimulation. These results suggest that T cells adapt to the strength of their basal TCR signaling, which results in heterogeneity of their functional capabilities following stimulation with foreign antigens.
Pervasive Arctic lead pollution suggests substantial growth in medieval silver production modulated by plague, climate, and conflict
Authors: McConnell Joseph R. , Chellman Nathan J. , Wilson Andrew I. , Stohl Andreas , Arienzo Monica M. , Eckhardt Sabine , Fritzsche Diedrich , Kipfstuhl Sepp , Opel Thomas , Place Philip F. , Steffensen Jørgen Peder
Published: July 2019

Significance

Detailed lead pollution measurements in an array of 13 ice cores spanning nearly half the Arctic showed surprisingly similar temporal variability during the past 2 millennia until the Industrial Revolution. Lead pollution increased by 250- to 300-fold from the Early Middle Ages to the 1970s industrial peak, reflecting large-scale emissions changes from ancient European silver production, recent fossil fuel burning, and other industrial activities. Pronounced decadal-scale increases coincided with exploitation of new mining districts, technology development, and periods of economic prosperity, while decreases coincided with climate disruptions, famines, major wars, and plagues. Despite midlatitude pollution abatement policies that reduced Arctic lead pollution by >80% since the 1970s, recent levels remain 60-fold higher than at the start of the Middle Ages.
Marine ice sheet instability amplifies and skews uncertainty in projections of future sea-level rise
Authors: Robel Alexander A. , Seroussi Hélène , Roe Gerard H.
Published: July 2019

Sea-level rise may accelerate significantly if marine ice sheets become unstable. If such instability occurs, there would be considerable uncertainty in future sea-level rise projections due to imperfectly modeled ice sheet processes and unpredictable climate variability. In this study, we use mathematical and computational approaches to identify the ice sheet processes that drive uncertainty in sea-level projections. Using stochastic perturbation theory from statistical physics as a tool, we show mathematically that the marine ice sheet instability greatly amplifies and skews uncertainty in sea-level projections with worst-case scenarios of rapid sea-level rise being more likely than best-case scenarios of slower sea-level rise. We also perform large ensemble simulations with a state-of-the-art ice sheet model of Thwaites Glacier, a marine-terminating glacier in West Antarctica that is thought to be unstable. These ensemble simulations indicate that the uncertainty solely related to internal climate variability can be a large fraction of the total ice loss expected from Thwaites Glacier. We conclude that internal climate variability alone can be responsible for significant uncertainty in projections of sea-level rise and that large ensembles are a necessary tool for quantifying the upper bounds of this uncertainty.
Earth’s radiative imbalance from the Last Glacial Maximum to the present
Authors: Baggenstos Daniel , Häberli Marcel , Schmitt Jochen , Shackleton Sarah A. , Birner Benjamin , Severinghaus Jeffrey P. , Kellerhals Thomas , Fischer Hubertus
Published: July 2019

Significance

Earth’s radiative imbalance determines whether energy is flowing into or out of the ocean–atmosphere system. The present, anthropogenic, positive imbalance drives global warming. This study reconstructs the radiative imbalance for the last deglaciation, ∼20,000 to 10,000 y ago. During the deglaciation, a positive imbalance was maintained for several thousand years, which brought the climate system from the last ice age into the Holocene warm period. We show that the imbalance varied significantly during this time, possibly due to changes in ocean circulation that affect the radiative energy fluxes, highlighting the importance of internal variability in Earth’s energy budget.
A cell–cell interaction format for selection of high-affinity antibodies to membrane proteins
Authors: Yang Zhuo , Wan Yue , Tao Pingdong , Qiang Min , Dong Xue , Lin Chih-Wei , Yang Guang , Zheng Tianqing , Lerner Richard A.
Published: July 2019

Significance

Antibodies are an important class of drugs. We developed a simple, easy-to-use method for antibody drug discovery targeting membrane proteins including gated ion channels and G protein-coupled receptors. While phage or yeast display provides a convenient tool for antibody screening, the development of therapeutic antibodies against membrane proteins still encounters bottlenecks, because it is usually difficult to purify membrane proteins in native conformation for selecting functional antibodies. To address this challenge, we designed a whole-cell screening platform based on yeast–mammalian cell interaction, which bypasses the step of membrane protein purification and enables the direct selection of antibodies against “difficult-to-purify membrane proteins” in native state.
A large-scale field experiment shows giving advice improves academic outcomes for the advisor
Authors: Eskreis-Winkler Lauren , Milkman Katherine L. , Gromet Dena M. , Duckworth Angela L.
Published: July 2019

Common sense suggests that people struggling to achieve their goals benefit from receiving motivational advice. What if the reverse is true? In a preregistered field experiment, we tested whether giving motivational advice raises academic achievement for the advisor. We randomly assigned
n
= 1,982 high school students to a treatment condition, in which they gave motivational advice (e.g., how to stop procrastinating) to younger students, or to a control condition. Advice givers earned higher report card grades in both math and a self-selected target class over an academic quarter. This psychologically wise advice-giving nudge, which has relevance for policy and practice, suggests a valuable approach to improving achievement: one that puts people in a position to give.
Visualizing and manipulating the spatial and temporal coherence of light with an adjustable light source in an undergraduate experiment
Authors: Pieper K , Bergmann A , Dengler R , Rockstuhl C
Published: July 2019

Coherence expresses the ability of light to form interference patterns stationary in time and extended over a spatial domain. The importance of coherence is undoubted but teaching coherence constitutes a challenge. In particular, there are only a few simple and clear experiments to illustrate coherence. To render the phenomena of coherence more accessible and to point out the difference between spatial and temporal coherence, we introduce an undergraduate experiment consisting of a light source illuminating a double-slit and a Michelson interferometer. The light source is adjustable in its spatial extent, its central wavelength and its spectral width. With that we can control the spatial and temporal coherence of the emitted light. The variation of the spatial and temporal coherence causes changes in the contrast of the interference patterns in both interferometers captured simultaneously by two cameras at the output of the double-slit and the Michelson interferometer. Therefore, the change in spatial and temporal coherence can be directly visualised.
Configurational electronic states in layered transition metal dichalcogenides
Authors: Vodeb Jaka , Kabanov Viktor V , Gerasimenko Yaroslav A , Venturini Rok , Jan Ravnik  , van Midden Marion A , Zupanic Erik , Sutar Petra , Mihailovic Dragan
Published: July 2019

Mesoscopic irregularly ordered and even amorphous self-assembled electronic structures were recently reported in two-dimensional metallic dichalcogenides (TMDs), created and manipulated with short light pulses or by charge injection. Apart from promising new all-electronic memory devices, such states are of great fundamental importance, since such aperiodic states cannot be described in terms of conventional charge-density-wave (CDW) physics. In this paper, we address the problem of metastable mesoscopic configurational charge ordering in TMDs with a sparsely filled charged lattice gas model in which electrons are subject only to screened Coulomb repulsion. The model correctly predicts commensurate CDW states corresponding to different TMDs at magic filling fractions

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results either in multiple near-degenerate configurational states, or an amorphous state at the correct density observed by scanning tunnelling microscopy. Quantum fluctuations between degenerate states predict a quantum charge liquid at low temperatures, revealing a new generalized viewpoint on both regular, irregular and amorphous charge ordering in transition metal dichalcogenides.
Delay-induced patterns in a predator–prey model on complex networks with diffusion
Authors: Chang Lili , Liu Chen , Sun Guiquan , Wang Zhen , Jin Zhen
Published: July 2019

Reaction-diffusion (RD) systems with time delays have been commonly used in modeling biological systems and can significantly change the dynamics of these systems. For predator–prey model with modified Leslie–Gower and Holling-type III schemes governed by RD equations, instability induced by time delay can generate spiral waves. Considering that populations are usually organized as networks instead of being continuously distributed in space, it is essential to study the predator–prey model on complex networks. In this paper, we investigate instability induced by time delay for the corresponding network organized system and explore pattern formations on several different networks including deterministic networks and random networks. We firstly obtain instability condition via linear stability analysis and then the condition is applied to study pattern formations for the model in question. The simulation results show that wave patterns can be generated on different networks. However, wave patterns on random networks differ significantly from patterns on deterministic networks. Finally, we discuss the influences of network topology on wave patterns from the aspects of amplitude and period, and reveal the ecology significance implied by these results.
III–V compounds as single photon emitters
Authors: Wang Xu , Xu Lei , Jiang Yun , Yin Zhouyang , Chan Christopher C. S. , Deng Chaoyong , Taylor Robert A.
Published: July 2019

Single-photon emitters (SPEs) are one of the key components in quantum information applications. The ideal SPEs emit a single photon or a photon-pair on demand, with high purity and distinguishability. SPEs can also be integrated in photonic circuits for scalable quantum communication and quantum computer systems. Quantum dots made from III–V compounds such as InGaAs or GaN have been found to be particularly attractive SPE sources due to their well studied optical performance and state of the art industrial flexibility in fabrication and integration. Here, we review the optical and optoelectronic properties and growth methods of general SPEs. Subsequently, a brief summary of the latest advantages in III–V compound SPEs and the research progress achieved in the past few years will be discussed. We finally describe frontier challenges and conclude with the latest SPE fabrication science and technology that can open new possibilities for quantum information applications.
Research on the typical case of industrial and commercial capital promoting the increase of the farmer’s income
Authors: Li Ying , Guan Zhuohuai
Published: July 2019

The farmer’s income in China is still low and increasing slowly. The entry of industrial and commercial capital into “three rural” areas in China is an important way to promote the increase of the farmer’s income, and there are some successful cases of this entry existing in different areas of China which give us lots of useful experience. Some policies and measures should be implemented to improve the effect of the entry, mainly including changing the local government investment, correctly guiding industrial and commercial capital to participate in the development of agricultural industrialization, improving the investment environment of industrial and commercial capital, and optimizing the business model of industrial and commercial capital entering “three rural” area have become to be the policy focus of the government’s support the industrial and commercial capital promoting the doubling of the farmer’s income in China.