bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Dapagliflozin on Insulin Secretion and Insulin Sensitivity
in Patients with Prediabetes
Authors: Ramírez-Rodríguez Alejandra M. , González-Ortiz Manuel , Martínez-Abundis Esperanza
Published: August 2018

Aim To evaluate the effect of dapagliflozin on insulin secretion and
insulin sensitivity in patients with prediabetes.

Methods A randomized, double-blind, placebo-controlled clinical trial
was carried out in 24 adults diagnosed with prediabetes and without
pharmacological treatment. Patients were randomly assigned into two groups
of 12 patients each to receive 10 mg of oral dapagliflozin or
placebo once a day during 12 weeks. At baseline and at the end of the study,
anthropometric and metabolic measurements were evaluated, including the
first phase of insulin secretion, total insulin secretion, and insulin
sensitivity.

Results After dapagliflozin administration, there were significant
decreases in body weight (80.8±16.3 vs.
77.8±14.9 kg, p=0.019), body mass index
(30.3±3.5 vs. 29.2±3.1 kg/m2,
p=0.023), waist circumference (100.6±13.5 vs.
96.2±11.8 cm, p=0.003), fasting glucose
(5.9±0.4 vs. 5.1±0.3 mmol/L,
p<0.001) and uric acid (334.3±70.8 vs.
262.9±60.7 mmol/L, p=0.032), with a tendency
to increase the insulin sensitivity (1.94±0.72 vs.
2.63±1.04, p=0.064).

Conclusion Dapagliflozin administration in patients with prediabetes
decreased body weight, body mass index, waist circumference, fasting
glucose, and uric acid, with a tendency to increase the insulin sensitivity
without changes in insulin secretion.
Was prägt die Sexualität?
Authors: Beate Martin HP
Published: August 2018

Die Sexualität entwickelt sich nicht isoliert von der Persönlichkeit, sondern ist ein Teil von ihr.
The Relationship Between Statin Action On Thyroid Autoimmunity And Vitamin D Status: A Pilot Study
Authors: Krysiak Robert , Szkróbka Witold , Okopień Bogusław
Published: August 2018

Background Both vitamin D preparations and high-dose statin therapy were found to reduce thyroid antibody titers.

Objective The purpose of this study was to assess whether vitamin D status determines the effect of statin therapy on thyroid autoimmunity.

Methods The study population consisted of 39 euthyroid women with Hashimoto's thyroiditis and moderate or moderately high cardiovascular risk divided into two groups: women with vitamin D deficiency or insufficiency (group A; n=19) and women with normal vitamin D status (group B, n=20). All patients received atorvastatin therapy (20–40 mg daily) for the following 6 months. Plasma lipids, circulating levels of thyrotropin, free thyroid hormones, prolactin and 25-hydroxyvitamin D, titers of thyroid peroxidase and thyroglobulin antibodies, as well as Jostel’s, the SPINA-GT and the SPINA-GD indices were assessed at the beginning and at the end of the study.

Results The study completed all women. At baseline, with the exception of 25-hydroxyvitamin D, there were no significant differences between both study groups in plasma lipids, circulating hormone levels and titers of thyroid peroxidase and thyroglobulin antibodies. Despite improving plasma lipids in both study groups, atorvastatin reduced thyroid antibody titers only in women with normal vitamin D status. Moreover, in this group of patients, atorvastatin increased the SPINA-GT index. Circulating levels of the measured hormones, Jostel’s thyrotropin index and the SPINA-GD index remained at a similar level throughout the study.

Conclusions The results of the study suggest that the effect of atorvastatin therapy on thyroid autoimmunity depends on vitamin D status.
Elektrokonvulsionstherapie bei einem Patienten mit intrakraniellen titanhaltigen Metallplatten
Authors: Kozian Ralf , Six Andrea , Stroukov Alexej , Hoefer Lore , Grözinger Michael
Published: August 2018

Berichtet wird über eine erfolgreiche Elektrokonvulsionstherapie (EKT) bei einem 24-jährigen Patienten, der an einer Schizophrenie leidet. Bei ihm wurde nach einem Fenstersturz in suizidaler Absicht eine frontobasale Plattenosteosynthese mit Titanplatten durchgeführt. Die EKT wurde veranlasst, weil bei dem Patienten trotz Neuroleptikagabe eine therapierefraktäre Positivsymptomatik mit inhaltlichen Denkstörungen, gestörtem Ich-Erleben und Wahnwahrnehmungen vorlag. Es erfolgten 14 Therapiesitzungen bei rechtsunilateraler Stimulation und Anwendung der Altersmethode. Die EKT wurde mit Einwilligung des Patienten und seines Betreuers während des Aufenthalts in der Klinik für Forensische Psychiatrie durchgeführt. Im Verlauf der Behandlung kam es zu einer Zustandsbesserung, Komplikationen traten nicht auf.
Dehydrative Cross-Coupling of 1-Phenylethanol Catalysed by Palladium Nanoparticles Formed in situ Under Acidic Conditions
Authors: Camp Jason , Bousfield Thomas , Dunsford Jay , Adams James , Britton Joshua , Fay Michael , Angelis-Dimakis Athanasios
Published: August 2018

A dehydrative cross-coupling of 1-phenylethanol catalysed by sugar derived, in situ formed palladium(0) nanoparticles under acidic conditions is realised. The acidic conditions allow for use of alcohols as a feedstock in metal-mediated coupling reactions via their in situ dehydration and subsequent cross-coupling. Extensive analysis of the size and morphology of the palladium nanoparticles formed in situ showed that the zero-valent metal was surrounded by hydrophilic hydroxyl groups. EDX-TEM imaging studies using a prototype silicon drift detector provided insight into the problematic role of molecular oxygen in the system. This increased understanding of the catalyst deactivation allowed for the development of the cross-coupling methodology. A 250-12,000 fold increase in molar efficiency was observed when compared to related two-step protocols that use alternative feedstocks for the palladium-mediated synthesis of stilbenes. This work opens up a new research area in which the active catalyst is formed, stabilised and regenerated by a renewable sugar.
Ligand-Free CuI-Catalyzed Chemoselective S-Arylation of 2-Mercaptobenzimidazole with Aryl Iodides
Authors: Teo Yong-Chua , Tan Bryan
Published: August 2018

A practical and efficient strategy for the chemoselective C–S cross-coupling of 2-mercaptobenzimidazole derivatives with a range of substituted aryl iodides is described. Under the optimized conditions of 5 mol% CuI and 100 °C, a variety of S-arylated products were obtained in good to excellent yields (up to 92 %) without the need for assisting ligands.
Metástasis inusuales en carcinoma de células renales
Authors: Bacaret W. , Cabrera M. , Ramos G. , Varela R. , Donoso W.
Published: August 2018

Introducción y Objetivos El carcinoma renal de células claras (CCR), es la neoplasia renal más frecuente. Hasta el 30% de los casos presentan enfermedad sistémica, siendo las más usuales: pulmón, ganglios, hígado y cerebro. El objetivo de este trabajo es informar casos poco frecuentes de metástasis por CCR y establecer posibles factores relacionados con las metástasis.

Métodos y Materiales revisión retrospectiva de historias clínicas en el instituto nacional de cancerología de los pacientes con carcinoma de células renales metastásico entre los años 2013 a 2017. Se identificaron 6 casos con sitios de metástasis inusuales en pacientes del servicio de urología oncológica del instituto nacional de cancerología, destacando histopatología e inmunohistoquímica de los especímenes quirúrgicos tanto del primario como de la metástasis, reportando marcadores específicos y clasificaciones según corresponda.

Resultados Caso 1 Metástasis a duodeno, Caso 2 metástasis a ovario, caso 3 metástasis a testículo, caso 4 metástasis a piel, caso 5 metástasis a glándula tiroides, caso 6 metástasis a mama y piel. Se evaluaron diferentes variables y se analizaron con base en la literatura.

Conclusiones Consideramos que la edad, el tabaquismo, el grado histológico, la invasión de la vena renal, el tamaño tumoral y el estadio pueden ser factores predisponentes para ese comportamiento.
Behavior of Buccal Mucosal Squamous Cell Carcinoma: A Retrospective Study of 53 Carcinomas of this Anatomical Region
Authors: Cariati Paolo , Cabello Serrano Almudena , Marin Fernandez Ana , Julia Martinez MiguelAngel , Fernandez Solis Jose , Martinez Lara Ildefonso
Published: August 2018

The main aim of the present report is to study the pattern of distribution of cervical metastasis in buccal mucosa cancer and to discuss the various therapeutic options available. Fifty-three patients with squamous cell carcinoma of the buccal mucosa treated with tumorectomy and selective neck dissection were included in the study. We also studied the relationship between specific pathological features and overall survival. Level Ib was the most affected level, followed by level IIa. T stage, N stage, N involvement tumor thickness, extracapsular spread (ECS), and vascular invasion were associated with poorer outcomes regarding overall survival ( p < 0.001). Carcinoma of the buccal mucosa should be treated aggressively from the early stages. A large tumorectomy of the primary tumor is required to reduce the number of local recurrences. Moreover, we recommend performing a supraomohyoid neck dissection even in cT1N0 if there is a suspicion that the tumor thickness may be greater than 0.4 cm. The high risk of local recurrence obliges protection of the neck from a future cervical recurrence even in T1 small tumors. This could reduce the risk of cervical involvement during the follow-up and improve overall survival rates.
Multivariate weighted recurrence network analysis of EEG signals from ERP-based smart home system
Authors: Gao Zhong-Ke , Liu Cheng-Yong , Yang Yu-Xuan , Cai Qing , Dang Wei-Dong , Du Xiu-Lan , Jia Hao-Xuan
Published: August 2018

Smart home has been widely used to improve the living quality of people. Recently, the brain-computer interface (BCI) contributes greatly to the smart home system. We design a BCI-based smart home system, in which the event-related potentials (ERP) are induced by the image interface based on the oddball paradigm. Then, we investigate the influence of mental fatigue on the ERP classification by the Fisher linear discriminant analysis. The results indicate that the classification accuracy of ERP decreases as the brain evolves from the normal stage to the mental fatigue stage. In order to probe into the difference of the brain, cognitive process between mental fatigue and normal states, we construct multivariate weighted recurrence networks and analyze the variation of the weighted clustering coefficient and weighted global efficiency corresponding to these two brain states. The findings suggest that these two network metrics allow distinguishing normal and mental fatigue states and yield novel insights into the brain fatigue behavior resulting from a long use of the ERP-based smart home system. These properties render the multivariate recurrence network, particularly useful for analyzing electroencephalographic recordings from the ERP-based smart home system.
Is Bach’s brain a Markov chain? Recurrence quantification to assess Markov order for short, symbolic, musical compositions
Authors: Moore Jack Murdoch , Corrêa Débora Cristina , Small Michael
Published: August 2018

It is rarely possible to precisely characterise the system underlying a series of observations. Hypothesis testing, which involves assessing simple assumptions about driving mechanisms, provides hope that we can at least rule out certain possibilities regarding the nature of the system. Unfortunately, the brevity, nonstationarity, and symbolic nature of certain time series of interest undermines traditional hypothesis tests. Fortunately, recurrence quantification analysis (RQA) has an established record of success in understanding short and nonstationary time series. We evaluate the suitability of measures of RQA as test statistics in surrogate data tests of the hypothesis that ten compositions by the Baroque composer J. S. Bach (1685–1750) arose from a Markov chain. More specifically, we estimate the size (the rate at which true hypotheses are incorrectly rejected) and power (the rate at which false hypotheses are correctly rejected) from empirical rejection rates across 1000 realisations, for each of the ten compositions, of the surrogate algorithm. We compare hypothesis tests based on RQA measures to tests based on the conditional entropy, an established test statistic for surrogate data tests of Markov order, and find that the RQA measure Lmax provides more consistent rejection of the fairly implausible hypothesis that Bach’s brain was a Markov chain.
Recurrence network modeling and analysis of spatial data
Authors: Chen Cheng-Bang , Yang Hui , Kumara Soundar
Published: August 2018

Nonlinear dynamical systems exhibit complex recurrence behaviors. Recurrence plot is widely used to graphically represent the patterns of recurrence dynamics and further facilitates the quantification of recurrence patterns, namely, recurrence quantification analysis. However, traditional recurrence methods tend to be limited in their ability to handle spatial data due to high dimensionality and geometric characteristics. Prior efforts have been made to generalize the recurrence plot to a four-dimensional space for spatial data analysis, but this framework can only provide graphical visualization of recurrence patterns in the projected reduced-dimension space (i.e., two- or three- dimensions). In this paper, we propose a new weighted recurrence network approach for spatial data analysis. A weighted network model is introduced to represent the recurrence patterns in spatial data, which account for both pixel intensities and spatial distance simultaneously. Note that each network node represents a location in the high-dimensional spatial data. Network edges and weights preserve complex spatial structures and recurrence patterns. Network representation is shown to be an effective means to provide a complete picture of recurrence patterns in the spatial data. Furthermore, we leverage network statistics to characterize and quantify recurrence properties and features in the spatial data. Experimental results in both simulation and real-world case studies show that the generalized recurrence network approach yields superior performance in the visualization of recurrence patterns in spatial data and in the extraction of salient features to characterize recurrence dynamics in spatial systems.
A modulation based phase difference estimator for real sinusoids to compensate for incoherent sampling
Authors: Wang Kui , Tu Yaqing , Shen Yanlin , Xiao Wei , McLernon Des
Published: August 2018

Phase difference estimation is a fundamental problem in numerous applications. However, incoherent sampling (IS) is an inevitable factor which degrades the precision of many correlations or Fourier transform-based approaches. In this paper, IS and the spectral superposition of real signals are both considered. A novel estimator is developed based on modulation and the discrete Fourier transform (DFT). With the estimated frequency, the phase difference can be obtained by calculating four DFT samples of the modulated signals. Simulations and the experimental results have proved their validity as well as their superiority over five other methods designed for IS, particularly at high signal-to-noise ratios. Furthermore, the proposed method can maintain high accuracy even when a significant bias occurs with the frequency estimation.
Mismatch error correction for time interleaved analog-to-digital converter over a wide frequency range
Authors: Jiang Zouyi , Zhao Lei , Gao Xingshun , Dong Ruoshi , Liu Jinxin , An Qi
Published: August 2018

High-speed high-resolution analog-to-digital conversion is the key part for waveform digitization in physics experiments and many other domains. This paper presents a new fully digital correction of mismatch errors among the channels in Time Interleaved Analog-to-Digital Converter (TIADC) systems. We focus on correction with wide-band input signals, which means that we can correct the mismatch errors for any frequency point in a broad band with only one set of filter coefficients. Studies were also made to show how to apply the correction algorithm beyond the base band, i.e., other Nyquist zones in the under-sampling situation. The structure of the correction algorithm is presented in this paper, as well as simulation results. To evaluate the correction performance, we actually conducted a series of tests with two TIADC systems. The results indicate that the performance of both TIADC systems can be greatly improved by correction, and the effective number of bits is successfully improved to be better than 9.5 bits and 5.5 bits for an input signal up to the bandwidth (−3 dB) range in the 1.6-Gsps 14-bit and the 10-Gsps 8-bit TIADC systems, respectively. Tests were also conducted for input signal frequencies in the second Nyquist zone, which shows that the correction algorithms also work well as expected.
Very small tail state formation in Cu2ZnGeSe4
Authors: Nagaya Keisuke , Fujimoto Shohei , Tampo Hitoshi , Kim Shinho , Nishiwaki Mitsutoshi , Nishigaki Yukinori , Kato Masato , Shibata Hajime , Fujiwara Hiroyuki
Published: August 2018

We find that coevaporated Cu2ZnGeSe4 has an ideal bandgap for solar cells (1.39 ± 0.01 eV) and shows quite reduced tail state absorption with a very low Urbach energy of 28 meV, which is far smaller than those of more studied Cu2ZnSnSe4 and Cu2ZnSnS4. The small tail states in Cu2ZnGeSe4 are found to originate from almost perfect cation ordering, while unusual tail state generation occurs in the Sn-based quaternary compounds by extensive cation substitution. Quite remarkably, the crystal total energy derived from first-principles calculations reveals a unified rule for the cation disordering, confirming that the lighter group-IV element (i.e., Ge) is essential for eliminating the tail state generation induced by cation mixing.
Increasing stagnation pressure and thermonuclear performance of inertial confinement fusion capsules by the introduction of a high-Z dopant
Authors: Berzak Hopkins L. , Divol L. , Weber C. , Le Pape S. , Meezan N. B. , Ross J. S. , Tommasini R. , Khan S. , Ho D. D. , Biener J. , Dewald E. , Goyon C. , Kong C. , Nikroo A. , Pak A. , Rice N. , Stadermann M. , Wild C. , Callahan D. , Hurricane O.
Published: August 2018

Inertial confinement fusion requires the inertia of the imploding mass to provide the necessary confinement such that the core reaches adequate high density, temperature, and pressure. Experiments utilize low-Z capsules filled with hydrogenic fuel, which are subject to multiple instabilities at the interfaces during the implosion. To improve the stability of the fuel:capsule interface and narrow the imploding shell profile, capsules are doped with a small atomic percentage of a high-Z material. A series of recent indirect-drive experiments executed at the National Ignition Facility with tungsten-doped high density carbon capsules has demonstrated that the presence of this dopant serves to increase the in-flight aspect ratio of the shell and increase the compression and neutron yield performance of both gas-filled and deuterium-tritium cryogenically layered targets. These experiments definitively demonstrate that benefits accrued by the introduction of a high-Z dopant into the capsule can outweigh the detrimentally reduced stability of the ablation front, avoiding shell breakup or significant radiative cooling of the hot spot. Future experiments will utilize these types of capsules to further increase nuclear performance.
A sub-megavolt anti-scattering grid: Fabrication, testing, and Monte Carlo simulation
Authors: Liu W. J. , Chen K. , Jing Y. F. , Hu H. S. , Cheng J. M. , Qian W. X. , Liu J.
Published: August 2018

X-ray flash radiography is an effective diagnostic in implosive research. While scattering reduces the contrast of radiography, the anti-scattering grids can effectively intercept the scattered radiation and acquire better images. A focused sub-megavolt grid is elaborately manufactured with the combination of lithography, etching, and laser drilling. The consistency of Monte Carlo simulations and radiographic experiments suggests a transmission of about 36% and a 1000 times improvement for the signal to scatter ratio of the grid.
Advances in milestoning. II. Calculating time-correlation functions from milestoning using stochastic path integrals
Authors: Grazioli Gianmarc , Andricioaei Ioan
Published: August 2018

In the milestoning framework, and more generally in related transition interface sampling schemes, one significantly enhances the calculation of relaxation rates for complex equilibrium kinetics from molecular dynamics simulations between the milestones or interfaces. The goal of the present paper is to advance milestoning applications into the realm of non-equilibrium statistical mechanics, in particular, to calculate entire time correlation functions. In order to accomplish this, we introduce a novel methodology for obtaining the flux through a given milestone configuration as a function of both time and initial configuration and build upon it with a novel formalism describing autocorrelation for Langevin motion in a discrete configuration space. The method is then applied to three different test systems: a harmonic oscillator, which we solve analytically, a two-well potential, which is solved numerically, and an atomistic molecular dynamics simulation of alanine dipeptide.
Breaking of waves on thin films over topographies
Authors: Dauth Markus , Aksel Nuri
Published: August 2018

In the present study, we performed experiments on the evolution of gravity-driven nonlinear traveling free surface waves over strongly undulated inclines. We focused on the impact of the excitation frequency and amplitude and the substrates’ shape and periodicity on the traveling wave. Thereby, we revealed phenomena concerning the amplitude evolution of convectively unstable waves. We can classify the wave evolution in three categories: (1) A normal exponential growth of the wave until it reaches a saturation amplitude. (2) An exponential growth of the wave and an abrupt collapse of the wave leading to a wave with a saturated amplitude, which is sensibly smaller than the maximal amplitude. (3) An alternating exponential growth and breaking of the wave. By using Fourier analysis, we investigated the waves in more detail. Furthermore, we report (a) a selection of excitation frequencies for the wave breaking, (b) a major impact of the steady state free surface, especially its mean or global curvature, (c) a bubble formation occurring at the wave breaking, (d) an overlap of the wave front, and (e) a formation of a jet during wave breaking.
Large time behaviors of strong solutions to magnetohydrodynamic equations with free boundary and degenerate viscosity
Authors: Ou Yaobin , Shi Pan , Wittwer Peter
Published: August 2018

In this paper, we establish the local, global existence and large-time behaviors of strong solutions to the free boundary problem of the planar magnetohydrodynamic equations with degenerate viscosity coefficient. Only the initial energy at the basic level is required to be small. The main difficulties are the degeneracy of the system near the free boundary and the strong coupling of the magnetic field and the velocity. We overcome the trouble by deriving the point-wise upper and lower bounds of the deformation variable uniformly in time and spatial variables and setting up the uniform-in-time weights energy estimates of solutions via singular multipliers. In contrast to previous works, the density is not required to be bounded from below and the viscosity coefficient is not a constant but degenerate; moreover, sharp convergent rates toward the steady state of the solutions are obtained.
Fabrication and characterization of a focused ion beam milled lanthanum hexaboride based cold field electron emitter source
Authors: Singh Gopal , Bücker Robert , Kassier Günther , Barthelmess Miriam , Zheng Fengshan , Migunov Vadim , Kruth Maximilian , Dunin-Borkowski Rafal E. , Purcell Stephen T. , Miller R. J. Dwayne
Published: August 2018

We report on a method of fabricating lanthanum hexaboride (LaB6) cold field emission tips with sub-100-nm apices by using a combination of electrochemical etching and focused ion beam milling. The primary advantage of combining the two methods is rapid fabrication while maintaining reproducibility. The LaB6 tips have low work functions and high mechanical stabilities and are chemically inert to residual gases. Field emission characterization was performed on three tips, with apex sizes of 15, 85, and 80 nm yielding 10 nA cold field emission currents at 0.76, 3.9, and 3.6 kV extraction potentials, respectively. All three tips showed excellent emission current stability for periods exceeding 30 min in a 5 × 10−9 mbar vacuum.
Stability conditions and local minima in multicomponent Hartree-Fock and density functional theory
Authors: Yang Yang , Culpitt Tanner , Tao Zhen , Hammes-Schiffer Sharon
Published: August 2018

Multicomponent quantum chemistry allows the quantum mechanical treatment of electrons and specified protons on the same level. Typically the goal is to identify a self-consistent-field (SCF) solution that is the global minimum associated with the molecular orbital coefficients of the underlying Hartree-Fock (HF) or density functional theory (DFT) calculation. To determine whether the solution is a minimum or a saddle point, herein we derive the stability conditions for multicomponent HF and DFT in the nuclear-electronic orbital (NEO) framework. The gradient is always zero for an SCF solution, whereas the Hessian must be positive semi-definite for the solution to be a minimum rather than a saddle point. The stability matrices for NEO-HF and NEO-DFT have the same matrix structures, which are identical to the working matrices of their corresponding linear response time-dependent theories (NEO-TDHF and NEO-TDDFT) but with a different metric. A negative eigenvalue of the stability matrix is a necessary but not sufficient condition for the corresponding NEO-TDHF or NEO-TDDFT working equation to have an imaginary eigenvalue solution. Electron-proton systems could potentially exhibit three types of instabilities: electronic, protonic, and electron-proton vibronic instabilities. The internal and external stabilities for theories with different constraints on the spin and spatial orbitals can be analyzed. This stability analysis is a useful tool for characterizing SCF solutions and is helpful when searching for lower-energy solutions. Initial applications to HCN, HNC, and 2-cyanomalonaldehyde, in conjunction with NEO ∆SCF calculations, highlight possible connections between stationary points in nuclear coordinate space for conventional electronic structure calculations and stationary points in orbital space for NEO calculations.
Driving frequency dependent wave modes of point-focusing electromagnetic acoustic transducers
Authors: Jia Xiaojuan , Ouyang Qi
Published: August 2018

This article presents a driving frequency dependent wave mode of point-focusing electromagnetic acoustic transducers (PF-EMATs), which is composed of a cylindrical permanent magnet and a concentric meander line (CML) coil with a varying spacing interval for concentring the ultrasound waves to a point. A finite element model is established to simulate the incentive and propagation process of ultrasonic waves so that the focusing characteristic, such as displacement, amplitude profile, and focal offset, can be obtained, allowing for investigation into the driving frequency dependence of wave modes. In addition, the universality of driving frequency dependent wave modes is well demonstrated. Furthermore, the relationship between the focusing performance of the developed PF-EMAT and the coil parameters, inner radius RC and number of turns NC of the CML coil, is explored. Finally, the experimental results show good agreement with the simulated results and indicate that the presented driving frequency dependent wave modes of PF-EMATs employing CML coils could manipulate the wave modes by carefully controlling the driving frequency.
Negative and positive thermal expansion-like volume changes due to intermetallic charge transfer based on an ionic crystal model of transition-metal oxides
Authors: Shimakawa Yuichi , Lufaso Michael W. , Woodward Patrick M.
Published: August 2018

Materials showing negative thermal expansion (NTE) are technologically important and a few transition-metal oxides with the perovskite structure show large NTE-like volume changes due to intermetallic charge transfer. Here we show that the observed volume changes are primarily caused by the size effect of the constituent ions in the oxides. Not only the NTE-like behaviors but also the positive volume change due to the intermetallic charge transfer can be qualitatively reproduced with a simple ionic crystal model by using the SPuDS software program. The results demonstrate that materials showing NTE-like behavior due to intermetallic charge transfer can be strategically designed.
High hole mobility in strained In0.25Ga0.75Sb quantum well with high quality Al0.95Ga0.05Sb buffer layer
Authors: Roh IlPyo , Kim SangHyeon , Geum Dae-Myeong , Lu Wenjie , Song YunHeub , del Alamo Jesús A. , Song JinDong
Published: August 2018

We have demonstrated high hole mobility in strained In0.25Ga0.75Sb quantum well (QW) structure with a high quality Al0.95Ga0.05Sb buffer layer for future single channel complementary metal-oxide-semiconductor circuits. The Al0.95Ga0.05Sb buffer layer is important to achieve low substrate leakage and guarantee good channel material quality and high hole mobility. We grew buffer layers with various Sb effective flux conditions using molecular beam epitaxy to obtain high crystal quality and proper electrical properties. We systematically evaluated the relationship between the crystal quality and electrical properties using X-ray diffraction, atomic force microscope, Raman, and the Hall effect measurement system. Then, on this optimized buffer layer, we grew the In0.2Al0.8Sb/In0.25Ga0.75Sb/linear-graded Al0.8Ga0.2Sb QW structure to obtain high hole mobility with compressive strain. Moreover, the compressive strain and hole mobility were measured by Raman and Hall effect measurement system. The results show a compressive strain value of 1.1% in In0.25Ga0.75Sb QW channel, which is very close to the theoretical value of 1.1% from lattice mismatch, exhibiting the highest hole mobility of 1170 cm2/V s among reported mobility in In0.25Ga0.75Sb QW. Furthermore, it was able to be fabricated as p-type Fin-FET and shown the excellent electrical characteristics with low Smin and high gm.
Low-energy methane scattering from Pt(111)
Authors: Kondo Takahiro , Al Taleb Amjad , Anemone Gloria , Farías Daniel
Published: August 2018

We have measured the temperature dependence of angular distributions of CH4 from Pt(111) at an incident energy of 109 meV. A broad angular distribution has been observed along the two main symmetry directions, whereby the peak center shifts from the supra-specular position to the sub-specular position when the surface temperature increases from 120 K to 800 K. Different widths have been measured for the scattering patterns along the [1¯01] and the [2¯11] azimuthal directions. Based on calculations performed within the binary collision model, these differences have been ascribed to different corrugations of the CH4–Pt(111) interaction potential along the two high-symmetry directions. This corrugation has been estimated from the model calculations to amount ∼0.03 Å, a factor of three larger than the one measured with helium diffraction.
Toward quantum-chemical method development for arbitrary basis functions
Authors: Herbst Michael F. , Dreuw Andreas , Avery James Emil
Published: August 2018

We present the design of a flexible quantum-chemical method development framework, which supports employing any type of basis function. This design has been implemented in the light-weight program package molsturm, yielding a basis-function-independent self-consistent field scheme. Versatile interfaces, making use of open standards like python, mediate the integration of molsturm with existing third-party packages. In this way, both rapid extension of the present set of methods for electronic structure calculations as well as adding new basis function types can be readily achieved. This makes molsturm well-suitable for testing novel approaches for discretising the electronic wave function and allows comparing them to existing methods using the same software stack. This is illustrated by two examples, an implementation of coupled-cluster doubles as well as a gradient-free geometry optimisation, where in both cases, arbitrary basis functions could be used. molsturm is open-sourced and can be obtained from http://molsturm.org.
Consistent modeling of differential molecular diffusion to yield desired Reynolds-number power-law scaling
Authors: Han Chao , Pant Tejas , Jain Utsav , Wang Haifeng
Published: August 2018

Differential molecular diffusion (DMD) is a fundamental physical phenomenon that occurs in many fluid flow problems such as turbulent reactive flows. Because DMD is a small-scale event, its modeling is intrinsically challenging, and hence in practical applications, it is more feasible to develop phenomenological models for treating the effect of DMD. In order to develop these phenomenological models, a set of model constraints based on physical observations are needed in order to constrain the model development to yield consistent results with the physical observations. In this work, we adopt an existing power-law Reynolds number scaling of DMD as the model constraints and examine the turbulence modeling requirement of DMD in order to yield the desired scaling. The Reynolds-averaged Navier-Stokes simulations are employed as the modeling framework, and a turbulent mixing layer test case is used as a test case. Perturbation analysis is conducted to examine the model consistency in order to yield the power-law scaling for DMD in the mixing layer test case. It is found that a differential mixing time scale model is needed to yield the power-law scaling, and the commonly used equal mixing time scale model cannot produce the scaling correctly. Numerical simulations of the turbulent mixing problem are also performed to further demonstrate the turbulence modeling requirement for producing the desired power-law scaling of DMD.
Electromechanical control of polarization vortex ordering in an interacting ferroelectric-dielectric composite dimer
Authors: Mangeri John , Alpay S. Pamir , Nakhmanson Serge , Heinonen Olle G.
Published: August 2018

Using a free-energy based computational model, we have investigated the response of a system comprising two interacting ferroelectric nanospheres, embedded in a dielectric medium, to a static external electric field. The system response is hysteretic and tunable by changing the inter-particle distance and the orientation of the applied field, which strongly modulates the field-driven long-range elastic interactions between the particles that propagate through the dielectric matrix. At small separations, the sensitivity of the system behavior with respect to the electric field direction originates from drastically different configurations of the local vortex-like polarization states in ferroelectric particles. This suggests new routes for the design of composite metamaterials whose dielectric properties can be controlled and tuned by selecting the mutual arrangement of their ferroelectric components.
Single-shot X-ray dark-field imaging with omnidirectional sensitivity using random-pattern wavefront modulator
Authors: Zhou Tunhe , Wang Hongchang , Sawhney Kawal
Published: August 2018

With the development of multi-modal x-ray imaging techniques, dark-field signals have drawn increasing interest due to the complementary information to the conventional attenuation-contrast signal. The directional sensitivity of the dark-field signal can reveal the orientation of the microstructure of the imaged object. We propose to use single-shot dark-field imaging with a random-pattern wavefront modulator to achieve omni-directional sensitivity, which will be valuable for the study of strongly ordered systems. Compared to previous studies, the proposed method shows significant advance by requiring neither dedicated fabrication of x-ray optics nor prolonged scanning. The treatment has been demonstrated on images acquired both at synchrotron facilities and with a laboratory source. The flexibility and the accessibility ensure the potential for easy implementation of the method to benefit a wide range of fields.
On the standard conjecture for a fibre product of three elliptic surfaces with pairwise-disjoint discriminant loci
Authors: Tankeev S. G.
Published: August 2018

We prove that the Grothendieck standard conjecture

of Lefschetz type on the algebraicity of the operator

of Hodge theory is true for the fibre product

of complex elliptic surfaces

over a smooth projective curve

provided that the discriminant loci

are pairwise disjoint.
In vitro fermentation and in situ rumen degradation kinetics of summer forage brassica plants
Authors: Keim Juan P. , Cabanilla Jaime , Balocchi Oscar A. , Pulido Rubén G. , Bertrand Annick
Published: August 2018

The aim of the present study was to assess and compare the nutrient concentration, the in vitro fermentation and the in situ rumen degradation characteristics of Brassica rapa ssp. rapa L. (turnips) and Brassica napus ssp. biennis L. (forage rape). Five varieties of each species were established in three field replicates and were organised in a randomised complete-block nested design. All varieties were harvested and further analysed for chemical composition, in vitro gas-production kinetics, volatile fatty acid (VFA) production and in situ degradation kinetics of dry matter (DM) and crude protein. Turnips showed higher ash, total sugars, raffinose, sucrose, glucose and fructose concentrations (P < 0.001) than did forage rape. Turnip varieties differed in their sucrose, glucose, fructose and total soluble sugar concentration (P < 0.001), whereas rape varieties differed in their neutral detergent fibre concentration (P = 0.004) and digestible organic matter on a DM basis (P < 0.01). Regarding DM-degradation parameters, turnips had a higher soluble fraction ‘a’ (P < 0.01) and a lower insoluble, but potentially degradable fraction ‘b’ (P < 0.01) than did rape, but the fractional degradation rate ‘c’ (0.18/h) was similar to that of rape. Rates of gas production were slightly higher (P = 0.018) for turnip than for rape. No effects for brassica species nor for varieties within species were detected (P > 0.05) for total in vitro VFA production, as well as for the relative proportions of acetate, propionate, butyrate, branch chained VFA and the actetate:propionate ratio. Our study showed that most of the differences that were observed in terms of chemical composition and degradation kinetics did not result in differences in in vitro fermentation products.
Modification of a novel x-type high-molecular-weight glutenin subunit gene from Aegilops markgrafii to improve dough strength of wheat flour
Authors: Ma Xin , Du Xuye , Bo Cunyao , Wang Hongwei , Li Anfei , Kong Lingrang
Published: August 2018

High-molecular-weight glutenin subunits (HMW-GS) in bread wheat are major determinants of dough viscoelastic properties and the end-use quality of wheat flour. Cysteine residues, which form intermolecular disulphide bonds in HMW-GS, could improve the strength of gluten. To our knowledge, the number and position of cysteine residues in HMW-GS are conserved between wheat (Triticum aestivum) and Aegilops markgrafii. In the present study, we modified a gene (1Cx1.1) from Ae. markgrafii for an HMW-GS that possessed the typical structure and conserved number of cysteines. Site-directed mutagenesis was carried out in 1Cx1.1 to investigate how the position of cysteine residues in HMW-GS affects the mixing properties of dough. Six HMW-GS containing an extra cysteine residue were expressed in Escherichia coli, and the proteins were purified at sufficient scale for incorporation into flour to test dough quality. There were large differences in dough property among samples containing different modified subunits. Cysteine substituting in the N-terminal or repetitive-domain of HMW-GS could significantly improve dough quality. The results showed that the strategy was useful for providing genetic resources for gene engineering, and hence could be valuable for improving the processing quality of wheat.
Reproductive strategy of the Pacific cownose ray Rhinoptera steindachneri in the southern Gulf of California
Authors: Burgos-Vázquez María I. , Chávez-García Valeria E. , Cruz-Escalona Víctor H. , Navia Andrés F. , Mejía-Falla Paola A.
Published: August 2018

Rhinoptera steindachneri is one of the most common batoid species in the artisanal gill net fishery of the Gulf of California. In this study we investigated its reproductive biology based on 317 specimens caught in Bahía de la Paz, Mexico. Females measured up to 94.2-cm disc width (DW) and males reached 82.5cm DW; there were no significant differences in size or weight between sexes. The median size at maturity was estimated at 68.5cm DW for males and 71.8cm DW for females, and the median size at pregnancy was 84.3cm DW. Only the left ovary and uterus were functional; a maximum of six preovulatory vitellogenic follicles per female was recorded, although uterine fecundity was one embryo per female. Ovulation and birth occurred in May, June and July, with birth sizes ranging from 38.1 to 42cm DW. R. steindachneri in Bahía de la Paz exhibited low fecundity, large size at maturity and birth and a continuous and synchronous annual reproductive cycle.
Are Indigenous land and sea management programs a pathway to Indigenous economic independence?
Authors: Jarvis Diane , Stoeckl Natalie , Addison Jane , Larson Silva , Hill Rosemary , Pert Petina , Lui Felecia Watkin
Published: August 2018

This paper focuses on Indigenous business development, an under-researched co-benefit associated with investment in Indigenous land and sea management programs (ILSMPs) in northern Australia. More than 65% of ILSMPs undertake commercial activities that generate revenue and create jobs. In addition to generating environmental benefits, ILSMPs thus also generate economic benefits (co-benefits) that support Indigenous aspirations and help to deliver multiple government objectives. We outline key features of northern Australian economies, identifying factors that differentiate them from Western urbanised economies. We discuss literature highlighting that, if the aim is to stimulate (short-term) economic development in northern Indigenous economies, then the requirement is to stimulate demand for goods and services that are produced by Aboriginal and Torres Strait Islander people (herein referred to as Indigenous people), and which generate benefits that align with the goals and aspirations of Indigenous people. We also discuss literature demonstrating the importance of promoting a socio-cultural environment that stimulates creativity, which is a core driver of innovation, business development and long-term development.
ILSMPs have characteristics suggestive of an ability to kick-start self-sustaining growth cycles, but previous research has not investigated this. Using 8 years of data relating to Indigenous businesses that are registered with the Office of the Registrar of Indigenous Corporations (a subset of all Indigenous businesses), we use statistical tests (Granger causality tests) to check whether ILSMP expenditure in the first year has a positive impact on Indigenous business activity in subsequent years. This analysis (of admittedly imperfect data) produces evidence to support the proposition that expenditure on ILSMPs generates positive spillovers for Indigenous businesses (even those not engaged in land management), albeit with a 3-year lag. ILSMPs have been shown to be an appropriate mechanism for achieving a wide range of short-term benefits; our research suggests they may also work as catalysts for Indigenous business development, fostering sustainable economic independence.
Material barriers to diffusive and stochastic transport
Authors: Haller George , Karrasch Daniel , Kogelbauer Florian
Published: August 2018

Significance

Observations of tracer transport in fluids generally reveal highly complex patterns shaped by an intricate network of transport barriers and enhancers. The elements of this network appear to be universal for small diffusivities, independent of the tracer and its initial distribution. Here, we develop a mathematical theory for weakly diffusive tracers to predict transport barriers and enhancers solely from the flow velocity, without reliance on diffusive or stochastic simulations. Our results yield a simplified computational scheme for diffusive transport problems, such as the estimation of salinity redistribution for climate studies and the forecasting of oil spill spreads on the ocean surface.
Dynamic process connectivity explains ecohydrologic responses to rainfall pulses and drought
Authors: Goodwell Allison E. , Kumar Praveen , Fellows Aaron W. , Flerchinger Gerald N.
Published: August 2018

Significance

In the face of changing climate, weather variability, and land cover, it is important to understand how ecosystem components vary jointly to determine how the system responds as a whole. While previous works have identified thresholds along climate gradients regarding precipitation, soils, and vegetation, we relate these thresholds to shifts in connectivity between variables, captured through joint variability, to better understand whole-system attributes of resilience, sensitivity, and vulnerability. We use data from flux tower transects along elevation gradients to address the relationship between joint connectivity and energy, water, and carbon flux responses to changes in moisture availability. This analysis reveals differences in joint variability between locations that can help explain responses to disturbances such as rain events or drought.
Projection pursuit in high dimensions
Authors: Bickel Peter J. , Kur Gil , Nadler Boaz
Published: August 2018

Significance

A key challenge in analyzing high-dimensional data is to extract meaningful low-dimensional structures, which typically represent signals of interest. Standard and widely used methods include principal components analysis (PCA), independent component analysis (ICA), and projection pursuit. Limitations of PCA in high-dimensional settings have been widely studied. In this work, we show that with a limited amount of high-dimensional data, the results of projection pursuit and related ICA methods should be interpreted with great care. Specifically, even with structureless data, one may find projections with highly non-Gaussian components that have no statistical or scientific significance. In contrast, restricting to sparse projections, detecting non-Gaussian components is still possible.
Fear extinction reverses dendritic spine formation induced by fear conditioning in the mouse auditory cortex
Authors: Lai Cora Sau Wan , Adler Avital , Gan Wen-Biao
Published: August 2018

Significance

Whether learning-induced changes in neuronal circuits are inhibited or erased during the process of unlearning remains unclear. In this study, we examined the impact of auditory-cued fear conditioning and extinction on the remodeling of synaptic connections in the living mouse auditory cortex. We found that fear conditioning leads to cue-specific formation of new postsynaptic dendritic spines, whereas fear extinction preferentially eliminates these new spines in a cue-specific manner. Our findings suggest that learning-related changes of synaptic connections in the cortex are at least partially reversed after unlearning.