bluuebunny/crossref_metadata_2025 huggingface dataset:
Expected security performance of random linear binary codes in syndrome coding
Authors: Zhang Ke , Tomlinson Martin , Ahmed Mohammed Z. , Ma Xiaolin
Published: April 2018

In this study, random codes are applied to the classical syndrome coding scheme to achieve secrecy of communications. By analysing the effect of the values of the columns of the parity check matrix on the resulting security level of communications, a code design method is presented which constructs a class of random codes, termed random permutation codes, which achieve high security levels and are easily generated. A theoretical analysis method is presented which determines the security level achieved by randomly chosen, linear binary codes, and compared with simulation results obtained by Monte Carlo analysis. The results verify the theoretical approach. In particular, the theoretical method is also suitable for analysis of long codes having a large number of parity check bits which are beyond evaluation by computer simulation. The results show that the security performance of any randomly chosen permutation code is close to that of the best equivocation code having the same code parameters. This has the practical advantage in syndrome coding of being able to use an ephemeral code for each communication session, thereby providing forward secrecy, a desired feature of modern, secure communication systems.
Wireless big data in cellular networks: the cornerstone of smart cities
Authors: Li Rongpeng , Zhao Zhifeng , Yang Chenyang , Wu Chunming , Zhang Honggang
Published: April 2018

The rapid urbanisation has transformed cities to the preferential human settlement and allowed cities to quietly witness all range of human activities. As the key enabler in the information and communications technology industry, cellular networks play a decisive role in delivering communication messages and entertainment content. In particular, cellular network operators respond to human initiated service requests by gradually deploying necessary infrastructure and calibrating transmission protocols. Hence, cellular network records encompass the interesting interaction between human‐initiated messages and network‐triggered responses. In this study, the authors collect the ‘big data’ in urban cellular networks and try to dig out the human and urban planning properties. Specifically, they focus on the statistical modelling of three representative scenarios like spatial deployment density of base stations, packet length or traffic volume of mobile services, as well as inter‐arrival time and dwell time of human mobility. Through extensive data mining, they validate the heavy‐tailed feature universally existing in these scenarios. Afterwards, they discuss the implications of this heavy‐tailed feature and talk about its fundamental contribution to intelligent resource adjustment, proactive content caching, and enhanced connection management in cellular networks. Finally, they highlight the applications of this feature towards smarter cellular networks and cities.
Effect of noise on the solutions of non‐linear delay systems
Authors: Zhu Quanxin , Song Shiyun , Shi Peng
Published: April 2018

In this study the authors are concerned with the effect of noise on the solutions of a class of non‐linear delay systems. The systems under investigation are non‐linear without linear growth condition requirement, which makes the analysis difficult to ensure the existence and uniqueness of solutions. The authors first introduce a set of new non‐linear growth conditions with delays, and then provide the existence and uniqueness of solutions as well as some properties of the solutions. The new condition only requires the knowledge of the coefficient of the highest term, which is much easier to check in practice than the traditional conditions. Finally, an example is given to show the effectiveness and potential of theoretic results obtained.
Spectroscopic time-series analysis of R Canis Majoris
Authors: Lehmann H. , Tsymbal V. , Pertermann F. , Tkachenko A. , Mkrtichian D. E. , A-thano N.
Published: April 2018

R Canis Majoris is the prototype of a small group of Algol-type stars showing short orbital periods and low mass ratios. A previous detection of short-term oscillations in its light curve has not yet been confirmed. We investigate a new time series of high-resolution spectra with the aim to derive improved stellar and system parameters, to search for the possible impact of a third component in the observed spectra, to look for indications of activity in the Algol system, and to search for short-term variations in radial velocities. We disentangled the composite spectra into the spectra of the binary components. Then we analysed the resulting high signal-to-noise spectra of both stars. Using a newly developed program code based on an improved method of least-squares deconvolution, we were able to determine the radial velocities of both components also during primary eclipse. This allowed us to develop a better model of the system including the Rossiter–McLaughlin effect and to derive improved orbital parameters. Combining the results with those from spectrum analysis, we obtain accurate stellar and system parameters. We further deduce at least one oscillation frequency of 21.38 c d−1. It could be detected during primary eclipses only and confirms a previous photometric finding. Results point to an amplitude amplification of non-radial pulsation modes due to the eclipse mapping effect. The presence of a He I line in the spectra indicates mass transfer in the R CMa system. Calculations of its Roche geometry give evidence that the cool secondary component may fill its Roche lobe. No evidence of a third body in the system could be found in the observed spectra.
The low-mass pre-main sequence population of Scorpius OB1
Authors: Damiani Francesco
Published: April 2018

Context. The low-mass members of OB associations, expected to be a major component of their total population, are in most cases poorly studied because of the difficulty of selecting these faint stars in crowded sky regions. Our knowledge of many OB associations relies on only a relatively small number of massive members.

Aims. We study here the Sco OB1 association, with the aim of a better characterization of its properties, such as global size and shape, member clusters and their morphology, age and formation history, and total mass.

Methods. We use deep optical and near-infrared (NIR) photometry from the VPHAS+ and VVV surveys, over a wide area (2.6° × 2.6°), complemented by Spitzer infrared (IR) data, and Chandra and XMM-Newton X-ray data. A new technique is developed to find clusters of pre-main sequence M-type stars using suitable color-color diagrams, complementing existing selection techniques using narrow-band Hα photometry or NIR and ultraviolet (UV) excesses, and X-ray data.

Results. We find a large population of approximately 4000 candidate low-mass Sco OB1 members whose spatial properties correlate well with those of Hα-emission, NIR-excess, UV-excess, and X-ray detected members, and unresolved X-ray emission. The low-mass population is spread among several interconnected subgroups: they coincide with the HII regions G345.45+1.50 and IC4628, and the rich clusters NGC 6231 and Trumpler 24, with an additional subcluster intermediate between these two. The total mass of Sco OB1 is estimated to be ~ 8500 M⊙. Indication of a sequence of star-formation events is found, from South (NGC 6231) to North (G345.45+1.50). We suggest that the diluted appearance of Trumpler 24 indicates that the cluster is now dissolving into the field, and that tidal stripping by NGC 6231 nearby contributes to the process.
The first direct double neutron star merger detection: Implications for cosmic nucleosynthesis
Authors: Rosswog S. , Sollerman J. , Feindt U. , Goobar A. , Korobkin O. , Wollaeger R. , Fremling C. , Kasliwal M. M.
Published: April 2018

Context. The astrophysical r-process site where about half of the elements, heavier than iron are produced, has been a puzzle for several decades. Here we discuss the role of one of the leading ideas – neutron star mergers (NSMs) – in the light of the first direct detection of such an event in both gravitational (GW) and electromagnetic (EM) waves.

Aims. Our aim is to understand the implications of the first GW/EM observations of a NSM for cosmic nucleosynthesis.

Methods. We analyse bolometric and NIR lightcurves of the first detected double NSM and compare them to nuclear reaction network-based macronova models.

Results. The slope of the bolometric lightcurve is consistent with the radioactive decay of neutron star ejecta with Ye ≲ 0.3 (but not larger), which provides strong evidence for an r-process origin of the electromagnetic emission. This rules out in particular “nickel winds” as major source of the emission. We find that the NIR lightcurves can be well fitted either with or without lanthanide-rich ejecta. Our limits on the ejecta mass together with estimated rates directly confirm earlier purely theoretical or indirect observational conclusions that double neutron star mergers are indeed a major site of cosmic nucleosynthesis. If the ejecta mass was typical, NSMs can easily produce all of the estimated Galactic r-process matter, and – depending on the real rate – potentially even more. This could be a hint that the event ejected a particularly large amount of mass, maybe due to a substantial difference between the component masses. This would be compatible with the mass limits obtained from the GW-observation.

Conclusions. The recent observations suggests that NSMs are responsible for a broad range of r-process nuclei and that they are at least a major, but likely the dominant r-process site in the Universe.
Unveiling the remarkable photodissociation region of Messier 8
Authors: Tiwari M. , Menten K. M. , Wyrowski F. , Pérez-Beaupuits J. P. , Wiesemeyer H. , Güsten R. , Klein B. , Henkel C.
Published: April 2018

Aims. Messier 8 (M8) is one of the brightest HII regions in the sky. We collected an extensive dataset comprising multiple sub- millimeter spectral lines from neutral and ionized carbon and from CO. Based on this dataset, we aim to understand the morphology of M8 and that of its associated photodissociation region (PDR) and to carry out a quantitative analysis of the physical conditions of these regions such as kinetic temperatures and volume densities.

Methods. We used the Stratospheric Observatory For Infrared Astronomy (SOFIA), the Atacama Pathfinder Experiment (APEX) 12 m, and the Institut de Radioastronomie Millimétrique (IRAM) 30 m telescopes to perform a comprehensive imaging survey of the emission from the fine structure lines of [C II] and [C I] and multiple rotational transitions of carbon monoxide (CO) isotopologs within 1.3 × 1.3 pc around the dominant Herschel 36 (Her 36) system, which is composed of at least three massive stars. To further explore the morphology of the region, we compared archival infrared, optical, and radio images of the nebula with our newly obtained fine structure line and CO data, and in particular with the velocity information these data provide. We performed a quantitative analysis, using both LTE and non-LTE methods to determine the abundances of some of the observed species, kinetic temperatures, and volume densities.

Results. Bright CO, [C II] and [C I] emission have been found toward the HII region and the PDR in M8. Our analysis places the bulk of the molecular material in the background of the nebulosity illuminated by the bright stellar systems Her 36 and 9 Sagitarii. Since the emission from all observed atomic and molecular tracers peaks at or close to the position of Her 36, we conclude that the star is still physically close to its natal dense cloud core and heats it. A veil of warm gas moves away from Her 36 toward the Sun and its associated dust contributes to the foreground extinction in the region. One of the most prominent star forming regions in M8, the Hourglass Nebula, is particularly bright due to cracks in this veil close to Her 36. We obtain H2 densities ranging from ~104–106 cm–3 and kinetic temperatures of 100–150 K in the bright PDR caused by Her 36 using radiative transfer modeling of various transitions of CO isotopologs.
Influence of stellar structure, evolution, and rotation on the tidal damping of exoplanetary spin-orbit angles
Authors: Damiani C. , Mathis S.
Published: April 2018

Context. It is debated whether close-in giant planets can form in-situ and if not, which mechanisms are responsible for their migration. One of the observable tests for migration theories is the current value of the obliquity, that is, the angle between the stellar equatorial plane and the orbital plane. However, after the main migration mechanism has ended, the obliquity and the semi-major axis keep on evolving due to the combined effects of tides and magnetic braking. The observed correlation between effective temperature and measured projected obliquity in well-characterised systems has been taken as evidence of such mechanisms being at play.

Aims. Our aim is to produce an improved model for the tidal evolution of the obliquity, including all the components of the dynamical tide for circular misaligned systems. This model is developed to take into account the strong variations in structure and rotation of stars during their evolution, and their consequences for the efficiency of tidal dissipation.

Methods. Our model uses an analytical formulation for the frequency-averaged dissipation in convective layers for each mode, depending only on global stellar parameters and rotation. It also includes the effect of magnetic braking in the framework of a double zone stellar model.

Results. For the orbital configurations of typical hot Jupiters, the obliquity is generally damped on a much shorter timescale than the semi-major axis. The final outcome of tidal evolution is also very sensitive to the initial conditions, with Jupiter-mass planets being either quickly destroyed or put on more distant orbits, depending on the initial ratio of planetary orbital momentum to stellar spin momentum. However, we find that everything else being the same, the evolution of the obliquity around low-mass stars with a thin convective zone is not slower than around those with a thicker convective zone. On the contrary, we find that more massive stars, which remain faster rotators throughout their main-sequence, produce more efficient dissipation.
J1342+0928 supports the timeline in theRh=ctcosmology
Authors: Melia Fulvio
Published: April 2018

Aims.The discovery of quasar J1342+0928 (z= 7.54) reinforces the time compression problem associated with the premature formation of structure in Λ cold dark matter (ΛCDM). Adopting thePlanckparameters, we see this quasar barely 690 Myr after the big bang, no more than several hundred Myr after the transition from Pop III to Pop II star formation. Yet conventional astrophysics would tell us that a 10M⊙seed, created by a Pop II/III supernova, should have taken at least 820 Myr to grow via Eddington-limited accretion. This failure by ΛCDM constitutes one of its most serious challenges, requiring exotic “fixes”, such as anomalously high accretion rates, or the creation of enormously massive (~ 105M⊙) seeds, neither of which is ever seen in the local Universe, or anywhere else for that matter. Indeed, to emphasize this point, J1342+0928 is seen to be accreting at about the Eddington rate, negating any attempt at explaining its unusually high mass due to such exotic means. In this paper, we aim to demonstrate that the discovery of this quasar instead strongly confirms the cosmological timeline predicted by theRh=ctUniverse.

Methods.We assume conventional Eddington-limited accretion and the time versus redshift relation in this model to calculate when a seed needed to start growing as a function of its mass in order to reach the observed mass of J1342+0928 atz= 7.54.

Results.Contrary to the tension created in the standard model by the appearance of this massive quasar so early in its history, we find that in theRh=ctcosmology, a 10M⊙seed atz~ 15 (the start of the Epoch of Reionization att~ 878 Myr) would have easily grown into an 8 × 108M⊙black hole atz= 7.54 (t~ 1.65 Gyr) via conventional Eddington-limited accretion.
The angular momentum-mass relation: a fundamental law from dwarf irregulars to massive spirals
Authors: Posti Lorenzo , Fraternali Filippo , Di Teodoro Enrico M. , Pezzulli Gabriele
Published: April 2018

In a Λ CDM Universe, the specific stellar angular momentum (j*) and stellar mass (M*) of a galaxy are correlated as a consequence of the scaling existing for dark matter haloes (jh ∝2∕3). The shape of this law is crucial to test galaxy formation models, which are currently discrepant especially at the lowest masses, allowing to constrain fundamental parameters, such as, for example, the retained fraction of angular momentum. In this study, we accurately determine the empirical j*−M* relation (Fall relation) for 92 nearby spiral galaxies (from S0 to Irr) selected from the Spitzer Photometry and Accurate Rotation Curves (SPARC) sample in the unprecedented mass range 7 ≲ log M*∕M⊙≲ 11.5. We significantly improve all previous estimates of the Fall relation by determining j* profiles homogeneously for all galaxies, using extended HI rotation curves, and selecting only galaxies for which a robust j* could be measured (converged j*(<R) radial profile). We find the relation to be well described by a single, unbroken power-law j* α M*α over the entire mass range, with α = 0.55 ± 0.02 and orthogonal intrinsic scatter of 0.17 ± 0.01 dex. We finally discuss some implications of this fundamental scaling law for galaxy formation models and, in particular, the fact that it excludes models in which discs of all masses retain the same fraction of the halo angular momentum.
The NWRA Classification Infrastructure: description and extension to the Discriminant Analysis Flare Forecasting System (DAFFS)
Authors: Leka K.D. , Barnes Graham , Wagner Eric
Published: April 2018

A classification infrastructure built upon Discriminant Analysis (DA) has been developed at NorthWest Research Associates for examining the statistical differences between samples of two known populations. Originating to examine the physical differences between flare-quiet and flare-imminent solar active regions, we describe herein some details of the infrastructure including: parametrization of large datasets, schemes for handling “null” and “bad” data in multi-parameter analysis, application of non-parametric multi-dimensional DA, an extension through Bayes’ theorem to probabilistic classification, and methods invoked for evaluating classifier success. The classifier infrastructure is applicable to a wide range of scientific questions in solar physics. We demonstrate its application to the question of distinguishing flare-imminent from flare-quiet solar active regions, updating results from the original publications that were based on different data and much smaller sample sizes. Finally, as a demonstration of “Research to Operations” efforts in the space-weather forecasting context, we present the Discriminant Analysis Flare Forecasting System (DAFFS), a near-real-time operationally-running solar flare forecasting tool that was developed from the research-directed infrastructure.
Organische Angststörung bei posteriorer kortikaler Atrophie
Authors: Linsmayer Denise , Kindler Christoph , Anheier Wiebke , Reiff Julia , Suppa Per , Braus Dieter
Published: April 2018

Wir berichten von einer 54-jährigen Patientin, die über eine seit einem Jahr erfolglos behandelte, progrediente Angstsymptomatik mit rezidivierenden Sehstörungen mit room-tilt-illusions sowie subjektiven Gesichtsfeldeinschränkungen klagte und sich bei uns zur Einholung einer Zweitmeinung vorstellte. Sie berichtete außerdem über Störungen der Konzentration und Aufmerksamkeit sowie über Schwierigkeiten beim Schreiben, einhergehend mit verändertem Schriftbild und Häufung grammatikalischer Fehler. Anhand des Falles werden die relevanten anamnestischen und klinischen Angaben, die neuropsychologischen und bildmorphologischen Befunde sowie differenzialdiagnostische Überlegungen bei Verdacht auf posteriore kortikale Atrophie, eine seltenere neurodegenerative Erkrankung mit psychischen Symptomen, dargestellt.
Controlling im Krankenhaus: Mehr Transparenz in der Tiefe
Authors: Heitmann Christian
Published: April 2018

Der anhaltende wirtschaftliche Druck auf die Krankenhäuser hat in den vergangenen 15 Jahren zu einem deutlichen Ausbau des Controllings geführt. Obwohl inzwischen ein hoher Entwicklungsstand erreicht ist, bestehen nach wie vor große Potenziale sowohl in Bezug auf die Effektivität als auch die Effizienz.
Entgelt- und Budgetverhandlungen: Auf Augenhöhe mit den Kostenträgern
Authors: Bohmeier André , Schröer Stephan
Published: April 2018

Jahr für Jahr stehen Kliniken vor der Aufgabe, sich für die Entgelt- und Budgetverhandlungen in Position zu bringen – ein wichtiger Meilenstein auf dem Weg zu einem positiven Jahresergebnis. Mit Transparenz, einer durchdachten Strategie, professioneller Begleitung und innovativen Ideen können sich Kliniken gezielt auf Augenhöhe mit den Verhandlungspartnern bringen.
A Chiral Secondary Amine–Amidophosphane Precatalyst for Silver-Catalyzed Asymmetric 1,3-Dipolar Cycloaddition Reactions
Authors: Wang Haifei , Zheng Xiaojun , Deng Qifu , Hou Qinglin , Zhang Kaiqiang , Wen Pushan , Hu Shunqin
Published: April 2018

A class of multifunctional amidophosphanes derived from chiral 1,2-diphenylethylenediamines and natural α-amino acids has been developed. Among these, in combination with silver(I) salts, a chiral secondary amine–amidophosphane precatalyst has been demonstrated as being a highly efficient multifunctional precatalyst in the asymmetric 1,3-dipolar cycloaddition of azomethine ylides, including a series of heterocyclic, aliphatic, and 2-substituted azomethine ylides, and aromatic α,β-unsaturated aldehyde derived imino esters with different electron-deficient alkenes, as well as the three-component reaction of α-imino esters generated in situ by using N,N′-diisopropylcarbodiimide as dehydrating agent. Under optimal conditions, highly functionalized endo-adducts were obtained in high to excellent yields (up to 99% yield) and enantioselectivities (up to >99.9% ee).
Treatment of a Paediatric Distal Femoral Malunion Deformity
Authors: Pavarotti Greta , Boudrieau Randy
Published: April 2018

Objective The aim of this article was to describe the surgical re-alignment technique and stabilization of a distal femoral deformity in a 6-week-old, male, Foxhound.

Methods A healing metaphyseal fracture, resulting in a valgus deformity with internal rotation, was observed just proximal to the distal femoral physis. The deformity was treated by an opening wedge osteotomy with lateral translation and external rotation of the distal epiphysis using a guide-wire technique; a corticocancellous allograft bridged the defect, which was stabilized with a 2.0-mm locking Y-plate designed for human phalangeal fractures.

Results Successful deformity correction was obtained with subsequent healing of the osteotomy and maintained longitudinal bone growth. Sciatic neurapraxia developed as a result of a migrating adjunct pin (9 days post-operatively), which was removed. At long-term follow-up (4 years), a 12% shortening of the femur did result in addition to an asymptomatic grade 2 medial patellar luxation (MPL). The cause of the MPL was not evident; the owners declined treatment and the dog continued to function as an active hunting dog.

Clinical Significance Prior to ossification of the epiphyses in very young animals, which precludes effective radiographic pre-planning, the guide-wire technique can be utilized as the primary tool for performing angular deformity correction. Adequate fixation and stabilization can be obtained with small human specialty locking plates.
Free versus Pedicled Perforator Flaps for Lower Extremity Reconstruction: A Multicenter Comparison of Institutional Practices and Outcomes
Authors: Koh Keith , Goh Terence , Song Christopher , Suh Hyun , Rovito Peter , Hong Joon-Pio , Hallock Geoffrey
Published: April 2018

Background Of all body regions, lower extremity wounds have been and remain the greatest challenge. Perforator free flaps have been accepted as a reasonable option to solve this dilemma but require the complexity of microsurgery. As a consequence, the possibility that pedicled perforator flaps could supplant even perforator free flaps has recently gained intense enthusiasm.

Methods A retrospective investigation was undertaken to compare the validity for the use of perforator flaps of all types at three dissimilar institutions, that is, a university, a regional center, and a community hospital. All flaps performed in the 5-year period, 2011 to 2015, were included to allow at least 1-year follow-up before data analysis. A total of 433 free perforator flaps and 52 pedicled perforator flaps had been performed specifically for the lower extremity.

Results Patient demographics, wound etiology, and comorbidities were similar for all institutions. Free flaps were more commonly needed after trauma and for chronic ulcers. Pedicled flaps were more likely an option after tumor excision. Large defects or those involving the foot were better served by free flaps. Overall success for free perforator flaps was 90.1% and for pedicled perforator flaps was 92.3%, with no significant difference noted (p = 0.606) between institutions. Peripheral vascular disease was the only significant comorbidity risk factor for both free and pedicled flap failure.

Conclusion Perforator flaps in general have become a reasonable solution for soft tissue defects of the lower extremity. Following careful consideration of the etiology, dimensions, location, patient comorbidities, and presence of adequate perforators, a pedicled or free perforator flap could potentially be successful. Pedicled perforator flaps, if adequate healthy soft tissues remain adjacent to the defect, forecast a continuance of the evolution in seeking simplicity yet reliability by the best flap possible for soft tissue closure of the lower limb wound.
Cerebral Proliferative Angiopathy: Case Report
Authors: Gatto Luana , Brisson Rodrigo , Demartini Zeferino , Koppe Gelson , Rocha Carlos
Published: April 2018

Proliferative angiopathy (PA) is a rare cerebral vascular disease in which anomalous vessels continually recruit additional feeder arteries, amid a functional brain parenchyma. We report the case of a young woman with progressive history of headache, motor deficit, seizures and drowsiness. She received a misdiagnosis of brain arteriovenous malformation (AVM) and evolved with dysarthria and cognitive decline after an unsuccessful embolization performed at another institution. We opted for conservative treatment with periodic control by imaging tests. Proliferative angiopathy differs in natural history, prognosis, histopathology and treatment of the usual AVMs. Endovascular procedures aggravate the neurological deficits, which are usually progressive and tend to worsen over time.
The Association Between Self-Rated Fitness and Cardiorespiratory Fitness in Adults
Authors: Jensen Karina , Rosthøj Susanne , Linneberg Allan , Aadahl Mette
Published: April 2018

To assess criterion validity of a single item question on self-rated physical fitness against objectively measured cardiorespiratory fitness. From the Health2008 study 749 men and women between 30 and 60 years of age rated their fitness as excellent, very good, good, fair or poor. Cardiorespiratory fitness was estimated with the watt-max test. Agreement between self-rated and objectively measured physical fitness was assessed by Cohen’s weighted kappa coefficient. Correlation was determined by Goodman & Kruskal’s gamma correlation coefficient. All analyses were stratified according to gender. Data from 323 men and 426 women were analysed. There was a slight agreement between self-rated and objectively measured fitness in men (weighted kappa: 0.18, [95%CI: 0.13;0.23]) and a fair agreement in women (weighted kappa: 0.27, [95%CI: 0.22;0.32]). In both genders, self-rated fitness was positively correlated with objectively measured fitness (moderate correlation; gamma correlation coefficient for men: 0.63 [95%CI: 0.54;0.72] and women: 0.67 [95%CI: 0.59;0.75]). There was a slight to fair agreement and moderate, positive correlations between self-rated physical fitness and watt-max estimated cardiorespiratory fitness. Hence, a single-item question on physical fitness may be a cost-effective method of assessing fitness in large population studies, but is not valid for individual assessments.
Quantum incompatibility of channels with general outcome operator algebras
Authors: Kuramochi Yui
Published: April 2018

A pair of quantum channels is said to be incompatible if they cannot be realized as marginals of a single channel. This paper addresses the general structure of the incompatibility of completely positive channels with a fixed quantum input space and with general outcome operator algebras. We define a compatibility relation for such channels by identifying the composite outcome space as the maximal (projective) C*-tensor product of outcome algebras. We show theorems that characterize this compatibility relation in terms of the concatenation and conjugation of channels, generalizing the recent result for channels with quantum outcome spaces. These results are applied to the positive operator valued measures (POVMs) by identifying each of them with the corresponding quantum-classical (QC) channel. We also give a characterization of the maximality of a POVM with respect to the post-processing preorder in terms of the conjugate channel of the QC channel. We consider another definition of compatibility of normal channels by identifying the composite outcome space with the normal tensor product of the outcome von Neumann algebras. We prove that for a given normal channel, the class of normally compatible channels is upper bounded by a special class of channels called tensor conjugate channels. We show the inequivalence of the C*- and normal compatibility relations for QC channels, which originates from the possibility and impossibility of copying operations for commutative von Neumann algebras in C*- and normal compatibility relations, respectively.
Synchronization of two coupled turbulent fires
Authors: Takagi Kazushi , Gotoda Hiroshi , Miyano Takaya , Murayama Shogo , Tokuda Isao T.
Published: April 2018

We numerically study the scale-free nature of a buoyancy-induced turbulent fire and synchronization of two coupled turbulent fires. A scale-free structure is detected in weighted networks between vortices, while its lifetime obeys a clear power law, indicating intermittent appearances, disappearances, and reappearances of the scale-free property. A significant decrease in the distance between the two fire sources gives rise to a synchronized state in the near field dominated by the unstable motion of transverse vortex rings. The synchronized state vanishes in the far field forming well-developed turbulent plumes, regardless of the distance between the two fire sources.
Electron acceleration by turbulent plasmoid reconnection
Authors: Zhou X. , Büchner J. , Widmer F. , Muñoz P. A.
Published: April 2018

In space and astrophysical plasmas, like in planetary magnetospheres, as that of Mercury, energetic electrons are often found near current sheets, which hint at electron acceleration by magnetic reconnection. Unfortunately, electron acceleration by reconnection is not well understood yet, in particular, acceleration by turbulent plasmoid reconnection. We have investigated electron acceleration by turbulent plasmoid reconnection, described by MHD simulations, via test particle calculations. In order to avoid resolving all relevant turbulence scales down to the dissipation scales, a mean-field turbulence model is used to describe the turbulence of sub-grid scales and their effects via a turbulent electromotive force (EMF). The mean-field model describes the turbulent EMF as a function of the mean values of current density, vorticity, magnetic field as well as of the energy, cross-helicity, and residual helicity of the turbulence. We found that, mainly around X-points of turbulent reconnection, strongly enhanced localized EMFs most efficiently accelerated electrons and caused the formation of power-law spectra. Magnetic-field-aligned EMFs, caused by the turbulence, dominate the electron acceleration process. Scaling the acceleration processes to parameters of the Hermean magnetotail, electron energies up to 60 keV can be reached by turbulent plasmoid reconnection through the thermal plasma.
Abnormal staircase-like I-V curve in InGaN quantum well solar cells
Authors: Cai X. M. , Zheng Z. W. , Long H. , Ying L. Y. , Zhang B. P.
Published: April 2018

InGaN/GaN multiple quantum well-solar cells with different barrier thicknesses have been comparatively studied, and it is demonstrated that a thinner barrier facilitates the transport of photogenerated carriers. Meanwhile, an abnormal but regular staircase-like I-V curve is observed. The induction factors and microscopic physical process relevant to this abnormal feature are analyzed in detail, which is found closely related to the inadequate internal field and special epitaxial structure. Furthermore, the formation conditions of I-V curves with various types of inflections are also proposed. This work provides insight into the origin of device problems, which can be applicable to other types of solar cells.
Extreme magnetoresistance and SdH oscillation in compensated semimetals of NbSb2 single crystals
Authors: Guo Lei , Liu Yu-Kuai , Gao Guan-Yin , Huang Ye-Yu , Gao Heng , Chen Lei , Zhao Weiyao , Ren Wei , Li Shi-Yan , Li Xiao-Guang , Dong Shuai , Zheng Ren-Kui
Published: April 2018

Topological semimetals represent one of the most interesting classes of materials that continue to attract worldwide interest. Here, we report magnetotransport properties of MPn2-type (M = Nb, Ta; Pn = P, As, Sb) NbSb2 single-crystal semimetals with a centrosymmetric C12/m1 space group, paramagnetic ground state, and non-saturation parabolic-like magnetoresistance. The NbSb2 crystals show metallic conductivity down to 2 K and undergo a metal-to-insulator-like transition under a magnetic field B (B ≥ 4 T) and exhibit a resistivity plateau in the low-temperature region (T ≤ 10 K), where the value of resistivity strongly depends on the magnitude and direction of the magnetic field. Upon sweeping the magnetic field from 0 to 14.5 T in the transverse configuration at T = 1.5 K, the NbSb2 crystal shows a large positive magnetoresistance (4.2 × 103% at B = 14.5 T) with Shubnikov–de Haas (SdH) oscillation. Hall measurements reveal that both the carrier compensation between electrons and holes and the high mobility and large mean free path of carriers contribute to the large magnetoresistance. Fast Fourier transform analyses of angle-resolved SdH oscillation indicate that the Fermi surface of the NbSb2 crystal is quasi-two-dimensional with three-dimensional components. These findings, together with the theoretically calculated electronic band structure obtained within the framework of density functional theory, suggest that NbSb2 is a good candidate compensated semimetal for further theoretical and experimental investigation of this family of materials.
Numerical implementation of a cold-ion, Boltzmann-electron model for nonplanar plasma-surface interactions
Authors: Holgate J. T. , Coppins M.
Published: April 2018

Plasma-surface interactions are ubiquitous in the field of plasma science and technology. Much of the physics of these interactions can be captured with a simple model comprising a cold ion fluid and electrons which satisfy the Boltzmann relation. However, this model permits analytical solutions in a very limited number of cases. This paper presents a versatile and robust numerical implementation of the model for arbitrary surface geometries in cartesian and axisymmetric cylindrical coordinates. Specific examples of surfaces with sinusoidal corrugations, trenches, and hemi-ellipsoidal protrusions verify this numerical implementation. The application of the code to problems involving plasma-liquid interactions, plasma etching, and electron emission from the surface is discussed.
Re-examining the tetraphenyl-arsonium/tetraphenyl-borate (TATB) hypothesis for single-ion solvation free energies
Authors: Pollard Travis P. , Beck Thomas L.
Published: April 2018

Attempts to establish an absolute single-ion hydration free energy scale have followed multiple strategies. Two central themes consist of (1) employing bulk pair thermodynamic data and an underlying interfacial-potential-free model to partition the hydration free energy into individual contributions [Marcus, Latimer, and tetraphenyl-arsonium/tetraphenyl-borate (TATB) methods] or (2) utilizing bulk thermodynamic and cluster data to estimate the free energy to insert a proton into water, including in principle an interfacial potential contribution [the cluster pair approximation (CPA)]. While the results for the hydration free energy of the proton agree remarkably well between the three approaches in the first category, the value differs from the CPA result by roughly +10 kcal/mol, implying a value for the effective electrochemical surface potential of water of −0.4 V. This paper provides a computational re-analysis of the TATB method for single-ion free energies using quasichemical theory. A previous study indicated a significant discrepancy between the free energies of hydration for the TA cation and the TB anion. We show that the main contribution to this large computed difference is an electrostatic artifact arising from modeling interactions in periodic boundaries. No attempt is made here to develop more accurate models for the local ion/solvent interactions that may lead to further small free energy differences between the TA and TB ions, but the results clarify the primary importance of interfacial potential effects for analysis of the various free energy scales. Results are also presented, related to the TATB assumption in the organic solvents dimethyl sulfoxide and 1,2-dichloroethane.
Design and testing of a magnetically driven implosion peak current diagnostic
Authors: Hess M. H. , Peterson K. J. , Ampleford D. J. , Hutsel B. T. , Jennings C. A. , Gomez M. R. , Dolan D. H. , Robertson G. K. , Payne S. L. , Stygar W. A. , Martin M. R. , Sinars D. B.
Published: April 2018

A critical component of the magnetically driven implosion experiments at Sandia National Laboratories is the delivery of high-current, 10s of MA, from the Z pulsed power facility to a target. In order to assess the performance of the experiment, it is necessary to measure the current delivered to the target. Recent Magnetized Liner Inertial Fusion (MagLIF) experiments have included velocimetry diagnostics, such as PDV (Photonic Doppler Velocimetry) or Velocity Interferometer System for Any Reflector, in the final power feed section in order to infer the load current as a function of time. However, due to the nonlinear volumetrically distributed magnetic force within a velocimetry flyer, a complete time-dependent load current unfold is typically a time-intensive process and the uncertainties in the unfold can be difficult to assess. In this paper, we discuss how a PDV diagnostic can be simplified to obtain a peak current by sufficiently increasing the thickness of the flyer. This effectively keeps the magnetic force localized to the flyer surface, resulting in fast and highly accurate measurements of the peak load current. In addition, we show the results of experimental peak load current measurements from the PDV diagnostic in recent MagLIF experiments.
Magneto-transport properties of proposed triply degenerate topological semimetal Pd3Bi2S2
Authors: Roy Shubhankar , Pariari Arnab , Singha Ratnadwip , Satpati Biswarup , Mandal Prabhat
Published: April 2018

We report transport properties of single-crystalline Pd3Bi2S2, which has been predicted to host an unconventional electronic phase of matter beyond three-dimensional Dirac and Weyl semimetals. Similar to several topological systems, the resistivity shows field-induced metal to semiconductor-like crossover at low temperature. Large, anisotropic, and non-saturating magnetoresistance has been observed in the transverse experimental configuration. At 2 K and 9 T, the MR value reaches as high as ∼1.1 × 103%. Hall resistivity reveals the presence of two types of charge carriers and has been analyzed using the two-band model. In spite of the large density (>1021 cm−3), the mobility of charge carriers is found to be quite high (∼ 0.75 × 104 cm2 V−1 s−1 for the hole and ∼ 0.3 × 104 cm2 V−1 s−1 for the electron). The observed magneto-electrical properties indicate that Pd3Bi2S2 may be a new member of the topological semimetal family, which can have a significant impact in technological applications.
Substrate-molecule decoupling induced by self-assembly—Implications for graphene nanoribbon fabrication
Authors: Li Xinqian , Packwood Daniel M.
Published: April 2018

Interactions between organic molecules and metal surfaces are often very strong, resulting in the loss of well-defined frontier orbitals on the molecule due to electronic hybridization with the surface. In this paper, we use theoretical calculations to show that the interaction between graphene nanoribbon precursor molecules and copper surfaces is weakened upon molecular self-assembly. This phenomenon, which we abbreviate as SAID (Self-Assembly Induced Decoupling), increases the adsorption distance of the molecules to the surface, and results in a partial recovery of frontier molecular orbital electron density. The SAID phenomenon opens a new topic in the field of organic-metal interface physics, and may have broader implications for thin film devices and catalysis.
Layer-selective microwave-assisted magnetization switching in a dot of double antiferromagnetically coupled (AFC) layers
Authors: Lu Yuming , Okamoto Satoshi , Kikuchi Nobuaki , Kitakami Osamu , Shimatsu Takehito
Published: April 2018

Layer-selective magnetization switching is a key technology for three-dimensional magnetic recording. In this study, layer-selective magnetization switching is demonstrated in a dot of double antiferromagnetically coupled (AFC) layers under an assistance of an rf field. Each AFC layer consists of two Co/Pt multilayers with a Ru interlayer. By optimally tuning the rf frequency, the layer-selective switching of each AFC layer is clearly confirmed. However, this layer-selective switching is probabilistic, with a maximum probability of about 65%. The stability of the layer-selective switching is improved if the dipolar field from the first switched AFC layer is suppressed.
The role of community mental health services in supporting oral health outcomes among consumers
Authors: Meldrum Rebecca , Ho Hillary , Satur Julie
Published: April 2018

People with a lived experience of mental illness are at a higher risk for developing oral diseases and having poorer oral health than the broader population. This paper explores the role of Australian community mental health services in supporting the prevention and management of poor oral health among people living with mental illness. Through focus groups and semi-structured interviews, participants identified the value of receiving oral health support within a community mental health setting, in particular the delivery of basic education, preventive strategies, assistance with making or attending appointments and obtaining priority access to oral health services. Engagement with Community Health Services and referrals generated through the priority access system were identified as key enablers to addressing oral health issues. This study provides new insight into the importance of undertaking an integrated approach to reducing the oral health disparities experienced by those living with mental illness.
Dynamic changes in the global transcriptome of bovine germinal vesicle oocytes after vitrification followed by in vitro maturation
Authors: Huang Jianwei , Ma YongShun , Wei Shao , Pan Bo , Qi Yu , Hou YunPeng , Meng QingYong , Zhou GuangBin , Han HongBing
Published: April 2018

This study was conducted to investigate the effect of vitrification on the dynamics of the global transcriptome in bovine germinal vesicle (GV) oocytes and their in vitro-derived metaphase II (MII) oocytes. The GV oocytes were vitrified using the open-pulled straw method. After warming, GV oocytes and the resulting MII-stage oocytes were cultured in vitro for 2 h and 24 h respectively and were then collected. The fresh GV oocytes and their in vitro-derived MII oocytes were used as controls. Then, each pool (fresh GV, n = 3; vitrified GV, n = 4; fresh MII, n = 1 and MII derived from vitrified GV, n = 2) from the different stages was used for mRNA transcriptome sequencing. The results showed that the in vitro maturation rates of GV oocytes were significantly decreased (32.36% vs 53.14%) after vitrification. Bovine GV oocyte vitrification leads to 12 significantly upregulated and 19 downregulated genes. After culturing in vitro, the vitrification-derived MII oocytes showed 47 significantly upregulated and six downregulated genes when compared with those from fresh GV oocytes. Based on molecular function–gene ontology terms analysis and the Kyoto encyclopaedia of genes (KEGG) pathway database, the differentially expressed genes were associated with the pathways of cell differentiation and mitosis, transcription regulation, regulation of actin cytoskeleton, apoptosis and so on, which potentially result in the lower in vitro development of GV bovine oocytes.
Economics- and policy-driven organic carbon input enhancement dominates soil organic carbon accumulation in Chinese croplands
Authors: Zhao Yongcun , Wang Meiyan , Hu Shuijin , Zhang Xudong , Ouyang Zhu , Zhang Ganlin , Huang Biao , Zhao Shiwei , Wu Jinshui , Xie Deti , Zhu Bo , Yu Dongsheng , Pan Xianzhang , Xu Shengxiang , Shi Xuezheng
Published: April 2018

Significance

Soil organic carbon (C) stock in Chinese croplands increased by about 140 kg C ha
−1
year
−1
from 1980 to 2011. This soil organic C sequestration was largely due to drastic changes in management practices, such as fertilization, tillage, and residue treatments, induced by economic and policy incentives. Our analysis also indicates that excessive N inputs and inability to incorporate residue C into deeper soils will likely constrain the future C sequestration in Chinese croplands. These findings provide new insights into the causes and limitations of economics- and policy-driven soil C sequestration in China and offer some guidance for soil C management in many developing countries that are going through the similar economic and social transformations.
Biomaterial surface energy-driven ligand assembly strongly regulates stem cell mechanosensitivity and fate on very soft substrates
Authors: Razafiarison Tojo , Holenstein Claude N. , Stauber Tino , Jovic Milan , Vertudes Edward , Loparic Marko , Kawecki Maciej , Bernard Laetitia , Silvan Unai , Snedeker Jess G.
Published: April 2018

Significance

Cell instructive biomaterial cues are a major topic of interest in both basic and applied research. In this work, we clarify how surface energy of soft biomaterials can dramatically affect mesenchymal stem cell receptor recruitment and downstream signaling related to cell fate. We elucidate how surface protein self-assembly and the resulting surface topology can act to steer mechanotransduction and related biological response of attached cells. These findings fill a critical gap in our basic understanding of cell–biomaterial interaction and highlight soft biomaterial surface energy as a dominant design factor that should not be neglected.