bluuebunny/crossref_metadata_2025 huggingface dataset:
Emission of Joule heating events in simulations of the solar corona
Authors: Kanella Charalambos , Gudiksen Boris V.
Published: December 2018

Context. Nanoscale events in cooperation with steady heating from a slow heating mechanism, such as slow-burning current-sheets, could be able to heat the corona; however, their observational traces are hard to detect via current instrumentation. After we locate heating events in magnetohydrodynamic (MHD) simulations and synthesise observational data, we extract observational signatures of small-scale events.

Aims. Our mission is threefold. The first goal is to observe the manifestation of small-scale events via three observational tools: intensity maps of three extreme ultraviolet (EUV) filters in the Atmospheric Imaging Assembly (AIA) instrument with resolution better than that in AIA images, emission measure (EM) analysis, and time-lag maps. The second goal is to identify the reason why we cannot quantify the energy release from observed events. The third goal is to study the differences between the radiation from isolated heating events and that from the whole corona.

Methods. We employed a three-dimensional magnetohydrodynamic (3D-MHD) simulation using the Bifrost code. We simulated the atmosphere of a network embedded in the quiet Sun (QS), and we identified 3D heating events in the corona in several time-steps. Then we synthesised the three observational tools for two cases. First, we considered information from the total column mass in the corona, and then we considered only regions that exhibit heating events.

Results. We report on the differences between the two regions of investigation, which also consist of the evidence to justify why observers cannot identify small-scale heating events in observations. We found that the combination of multiple heating events at different cooling phases along the line of sight gives the impression of thin elongated threads of events. For this reason, the EM as a function of temperature has a multi-thermal distribution. Both the radiation and the emission measure of the isolated heating events have values at least ten times lower than the signal calculated from the total corona. We also found that heating events move together with diffuse emission from the slow heating mechanism, and for this reason we cannot differentiate between the two. In addition, we find that the frequency of heating events and their intensity affect the EM distribution as a function of temperature. We also find that the filter’s intensity, EM, and time-lag maps of heating events are different to those incorporating information from the total column mass of the corona. However, the two regions have, on average, comparable values, which are slightly smaller than the analytical cooling timescales calculated for an optically thin and radiation-dominated atmosphere.
The Galactic WC and WO stars
Authors: Sander A. A. C. , Hamann W.-R. , Todt H. , Hainich R. , Shenar T. , Ramachandran V. , Oskinova L. M.
Published: December 2018

Wolf-Rayet stars of the carbon sequence (WC stars) are an important cornerstone in the late evolution of massive stars before their core collapse. As core-helium burning, hydrogen-free objects with huge mass-loss, they are likely the last observable stage before collapse and thus promising progenitor candidates for type Ib/c supernovae. Their strong mass-loss furthermore provides challenges and constraints to the theory of radiatively driven winds. Thus, the determination of the WC star parameters is of major importance for several astrophysical fields. With Gaia DR2, for the first time parallaxes for a large sample of Galactic WC stars are available, removing major uncertainties inherent to earlier studies. In this work, we re-examine a previously studied sample of WC stars to derive key properties of the Galactic WC population. All quantities depending on the distance are updated, while the underlying spectral analyzes remain untouched. Contrasting earlier assumptions, our study yields that WC stars of the same subtype can significantly vary in absolute magnitude. With Gaia DR2, the picture of the Galactic WC population becomes more complex: We obtain luminosities ranging from logL/L⊙ = 4.9–6.0 with one outlier (WR 119) having logL/L⊙ = 4.7. This indicates that the WC stars are likely formed from a broader initial mass range than previously assumed. We obtain mass-loss rates ranging between log Ṁ = −5.1 and −4.1, with Ṁ ∝ L0.68 and a linear scaling of the modified wind momentum with luminosity. We discuss the implications for stellar evolution, including unsolved issues regarding the need of envelope inflation to address the WR radius problem, and the open questions in regard to the connection of WR stars with Gamma-ray bursts. WC and WO stars are progenitors of massive black holes, collapsing either silently or in a supernova that most-likely has to be preceded by a WO stage.
Discontinuities in numerical radiative transfer
Authors: Janett Gioele
Published: December 2018

Observations and magnetohydrodynamic simulations of solar and stellar atmospheres reveal an intermittent behavior or steep gradients in physical parameters, such as magnetic field, temperature, and bulk velocities. The numerical solution of the stationary radiative transfer equation is particularly challenging in such situations, because standard numerical methods may perform very inefficiently in the absence of local smoothness. However, a rigorous investigation of the numerical treatment of the radiative transfer equation in discontinuous media is still lacking. The aim of this work is to expose the limitations of standard convergence analyses for this problem and to identify the relevant issues. Moreover, specific numerical tests are performed. These show that discontinuities in the atmospheric physical parameters effectively induce first-order discontinuities in the radiative transfer equation, reducing the accuracy of the solution and thwarting high-order convergence. In addition, a survey of the existing numerical schemes for discontinuous ordinary differential systems and interpolation techniques for discontinuous discrete data is given, evaluating their applicability to the radiative transfer problem.
A-PHOT: a new, versatile code for precision aperture photometry
Authors: Merlin E. , Pilo S. , Fontana A. , Castellano M. , Paris D. , Roscani V. , Santini P. , Torelli M.
Published: December 2018

Aims. We present A-PHOT, a new publicly available code for performing aperture photometry on astronomical images, that is particularly well suited for multi-band extragalactic surveys.

Methods.A-PHOT estimates the fluxes emitted by astronomical objects within a chosen set of circular or elliptical apertures. Unlike other widely used codes, it runs on predefined lists of detected sources, allowing for repeated measurements on the same list of objects on different images. This can be very useful when forced photometric measurement on a given position is needed. A-PHOT can also estimate morphological parameters and a local background flux, and compute on-the-fly individual optimized elliptical apertures, in which the signal-to-noise ratio is maximized.

Results. We check the performance of A-PHOT on both synthetic and real test datasets: we explore a simulated case of a space-based high-resolution imaging dataset, investigating the input parameter space to optimize the accuracy of the performance, and we exploit the CANDELS GOODS-South data to compare the A-PHOT measurements with those from the survey legacy catalogs, finding good agreement overall.

Conclusions.A-PHOT proves to a useful and versatile tool for quickly extracting robust and accurate photometric measurements and basic morphological information of galaxies and stars, with the advantage of allowing for various measurements of fluxes at any chosen position without the need of a full detection run, and for determining the basic morphological features of the sources.
Probing accretion of ambient cloud material into the Taurus B211/B213 filament
Authors: Shimajiri Y. , André Ph. , Palmeirim P. , Arzoumanian D. , Bracco A. , Könyves V. , Ntormousi E. , Ladjelate B.
Published: December 2018

Context. Herschelobservations have emphasized the role of molecular filaments in star formation. However, the origin and evolution of these filaments are not yet well understood, partly because of the lack of kinematic information.

Aims.We confirm from a kinematic viewpoint that the Taurus B211/B213 filament is accreting background cloud material, and we investigate the potential influence of large-scale external effects on the formation of the filament.

Methods.To examine whether the B211/B213 filament is accreting background gas because of its gravitational potential, we produced a toy accretion model and compared its predictions to the velocity patterns observed in12CO (1–0) and13CO (1–0). We also examined the spatial distributions of Hα,Planck857 GHz dust continuum, and HI emission to search for evidence of large-scale external effects.

Results.We estimate that the depth of the Taurus cloud around the B211/B213 filament is ~0.3–0.7 pc under the assumption that the density of the gas is the same as the critical density of13CO (1–0). Compared to a linear extent of >10 pc in the plane of the sky, this suggests that the 3D morphology of the cloud surrounding the B211/B213 filament is sheet-like. Position–velocity (PV) diagrams observed in12CO (1–0) and13CO (1–0) perpendicular to the filament axis show that the emission from the gas surrounding B211/B213 is redshifted to the northeast of the filament and blueshifted to the southwest, and that the velocities of both components approach the velocity of the B211/B213 filament as the line of sight approaches the crest of the filament. ThePVdiagrams predicted by our accretion model are in good agreement with the observed12CO (1–0) and13CO (1–0)PVdiagrams, supporting the previously proposed scenario of mass accretion into the filament. Moreover, inspection of the spatial distribution of the HαandPlanck857 GHz emission in the Taurus–California–Perseus region on scales up to >200 pc suggests that the B211/B213 filament may have formed as a result of an expanding supershell generated by the Per OB2 association.

Conclusions.Based on these results, we propose a scenario in which the B211/B213 filament was initially formed by large-scale compression of HI gas and is now growing in mass by gravitationally accreting molecular gas of the ambient cloud.
X-ray and optical monitoring of the December 2017 outburst of the Be/X-ray binary AXJ0049.4–7323
Authors: Ducci L. , Malacaria C. , Romano P. , Ji L. , Bozzo E. , Saathoff I. , Santangelo A. , Udalski A.
Published: December 2018

AXJ0049.4–7323 (SXP 756) is a Be/X-ray binary that shows an unusual and poorly understood optical variability that consists of periodic and bright optical outbursts, simultaneous with X-ray outbursts, characterised by a highly asymmetric profile. The periodicity of the outbursts is thought to correspond to the orbital period of the neutron star. To understand the peculiar behaviour shown by this source, we performed the first multi-wavelength monitoring campaign during the periastron passage of December 2017. The monitoring lasted for about 37 days and consisted of X-ray, near-ultraviolet, and optical data from the Neil Gehrels Swift Observatory, the optical I band from the OGLE survey, and spectroscopic observations of the Hα line performed with the 3.9 m Anglo-Australian Telescope. These observations revealed AXJ0049.4–7323 during an anomalous outburst having remarkably different properties compared to the previous ones. In the I band, it showed a longer rise timescale (∼60 days instead of 1–5 days) and a longer decay timescale. At the peak of the outburst, it showed a sudden increase in luminosity in the I band, corresponding to the onset of the X-ray outburst. The monitoring of the Hα emission line showed a fast and highly variable profile composed of three peaks with variable reciprocal brightness. To our knowledge, this is the second observation of a variable three-peak Hα profile of a Be/X-ray binary, after A0535+26. We interpreted these results as a circumstellar disc warped by tidal interactions with the neutron star in a high eccentricity orbit during its periastron passage. The fast jump in optical luminosity at the peak of the outburst and the previous asymmetric outbursts might be caused by the reprocessing of the X-ray photons in the circumstellar disc or the tidal displacement of a large amount of material from the circumstellar disc or the outer layers of the donor star during the periastron passage of the neutron star, which led to an increase in size of the region emitting in the I band. Further multi-wavelength observations are necessary to discriminate among the different scenarios proposed to explain the puzzling optical and X-ray properties of AXJ0049.4–7323.
Laboratory spectroscopic study of isotopic thioformaldehyde, H2CS, and determination of its equilibrium structure
Authors: Müller Holger S. P. , Maeda Atsuko , Thorwirth Sven , Lewen Frank , Schlemmer Stephan , Medvedev Ivan R. , Winnewisser Manfred , De Lucia Frank C. , Herbst Eric
Published: December 2018

Context.Thioformaldehyde is an abundant molecule in various regions of the interstellar medium. However, available laboratory data limit the accuracies of calculated transition frequencies in the submillimeter region, in particular for minor isotopic species.

Aims.We aim to determine spectroscopic parameters of isotopologs of H2CS that are accurate enough for predictions well into the submillimeter region.

Methods.We investigated the laboratory rotational spectra of numerous isotopic species in natural isotopic composition almost continuously between 110 and 377 GHz. Individual lines were studied for most species in two frequency regions between 566 and 930 GHz. Further data were obtained for the three most abundant species in the 1290−1390 GHz region.

Results.New or improved spectroscopic parameters were determined for seven isotopic species. Quantum-chemical calculations were carried out to evaluate the differences between ground state and equilibrium rotational parameters to derive semi-empirical equilibrium structural parameters.

Conclusions.The spectroscopic parameters are accurate enough for predictions well above 1 THz with the exception of H213C34S where the predictions should be reliable to around 700 GHz.
Convective blueshifts in the solar atmosphere
Authors: Stief F. , Löhner-Böttcher J. , Schmidt W. , Steinmetz T. , Holzwarth R.
Published: December 2018

Context. Granular convective motions reach into the lower solar atmosphere, typically causing photospheric spectral lines to exhibit a differential line shift. This Doppler shift to shorter wavelengths is commonly known as convective blueshift.

Aims. Spectroscopic high-accuracy measurements provide us with a refined determination of the absolute convective blueshift and its atmospheric distribution from disk center to the solar limb.

Methods. We performed systematic observations of the quiet Sun with the Laser Absolute Reference Spectrograph (LARS) at the German Vacuum Tower Telescope. The solar disk was scanned along the meridian and the equator, from the disk center toward the limb. The solar spectrum around 6173 Å was calibrated with a laser frequency comb on an absolute wavelength scale with an accuracy of a few meters per second. We applied a bisector analysis on the spectral lines to reveal the changes of convective blueshift and line asymmetry at different heliocentric positions.

Results. Being a signature for convective motions, the bisector curve of Fe I 6173.3 Å describes a “C”-shape at disk center. When approaching the solar limb, the bisector transforms into a “\”-shape. The analysis of the time- and bisector-averaged line shifts yields three distinct results. Firstly, the center-to-limb variation of Doppler velocities measured with LARS reveals a significant discrepancy (up to 200 m s−1) to the full-disk Dopplergrams of the Helioseismic and Magnetic Imager (HMI). Secondly, we obtained a significant decrease of convective blueshift toward the solar limb. Thirdly, the line-of-sight effect of solar activity, including p-mode oscillations and supergranular flows, leads to a scatter of up to ±100 m s−1 at intermediate heliocentric positions.

Conclusions. The accurate observation of the absolute convective blueshift with LARS allows the identification of systematic discrepancy with Doppler velocities measured by HMI. The center-to-limb variation of HMI suffers from an additional blueshift for μ <  0.9 that is incompatible with our results. LARS measurements can be taken as a reference for the correction of systematic errors in the synoptic HMI Dopplergrams.
qpower2: A fast and accurate algorithm for the computation of exoplanet transit light curves with the power-2 limb-darkening law
Authors: Maxted P. F. L. , Gill S.
Published: December 2018

Context. The power-2 law, Iλ( μ) = 1 − c(1−μα), accurately represents the limb-darkening profile for cool stars. It has been implemented in a few transit models to-date using numerical integration but there is as-yet no implementation of the power-2 law in analytic form that is generally available.

Aims. Our aim is to derive an analytic approximation that can be used to quickly and accurately calculate light curves of transiting exoplanets using the power-2 limb-darkening law.

Methods. An algorithm to implement the power-2 law is derived using a combination of an approximation to the required integral and a Taylor expansion of the power-2 law. The accuracy of stellar and planetary radii derived by fitting transit light curves with this approximation is tested using light curves computed by numerical integration of limb-darkening profiles from 3D stellar model atmospheres.

Results. Our algorithm (qpower2) is accurate to about 100 ppm for broad-band optical light curves of systems with a star-planet radius ratio p = 0.1. The implementation requires less than 40 lines of python code so can run extremely fast on graphical processing units (GPUs; ∼1 million models per second for the analysis of 1000 data points). Least-squares fits to simulated light curves show that the star and planet radius are recovered to better than 1% for p <  0.2.

Conclusions. The qpower2 algorithm can be used to efficiently and accurately analyse large numbers of high-precision transit light curves using Monte Carlo methods.
Augmented Reality und Virtual Reality im Operationssaal – Status Quo und Quo vadis
Authors: Sparwasser Peter , Schoeb Dominik , Miernik Arkadiusz , Borgmann Hendrik
Published: December 2018

Einleitung Virtual Reality (VR) ist die künstlich simulierte Umgebung, mit der eine Interaktion möglich ist. Die Augmented Reality (AR) hingegen überlagert reale und künstliche Informationen. Beide Verfahren sind im Klinikalltag bereits vielerorts integriert und werden zunehmend auch für den chirurgischen Sektor beworben. Welche Möglichkeiten die vielfältigen Anwendungsmöglichkeiten bieten, ist dabei vielen Ärzten unklar.

Ziel Erfassung der aktuellen und zukünftigen Verwendung von AR und VR im perioperativen Umfeld sowie die Veranschaulichung der zu erwartenden Verbesserungen und Probleme durch diese neuen Technologien.

Methoden: Systematische Literaturrecherche der Medizinbibliothek PubMed mit Inklusion von Reviews, die Bezug nehmen auf das Thema AR und VR mit Fokus auf Artikel, die das perioperative Feld berühren. Schlagwörter waren: Augmented Reality, Virtual Reality, Telementoring, Telechirurgie („Telesurgery“). Zudem Durchführung einer Recherche innerhalb der Grauliteratur zur Analyse der Investitionsbereitschaft im Gesundheitswesen durch private Technologiekonzerne.

Resultate Zum Thema „Augmented Reality“ wurden 1222 Artikel bei 119 Reviews und zu „Virtual Reality“ 7766 Artikel bei 878 Reviews angezeigt. Die Anzahl der veröffentlichten Artikel ist dabei über die letzten Jahre hinweg stark zunehmend. 45 Artikel wurden eingeschlossen. Multiple AR- und VR-Geräte sind bereits im operativen Setting etabliert. Die nächsten vielversprechenden Anwendungsbereiche werden hier v. a. die intraoperative Überlagerung von bildgebenden Verfahren über AR-Geräte sowie das Telementoring und die vermehrte Anwendung im Bereich operativer bzw. anatomischer Ausbildung betreffen. Die zu erhoffenden Vorteile wie Senkung der Komplikationsrate, Kosteneinsparungen, flächendeckender Wissenszuwachs und Optimierung des chirurgischen Ergebnisses müssen erst in wissenschaftlichen Studien nachgewiesen werden. Aus der Recherche der Grauliteratur geht ein enormes finanzielles Bestreben der Technologiekonzerne in diesem Sektor hervor.

Schlussfolgerung AR und VR werden aufgrund ihres enormen Verbesserungspotenzials zunehmend in den perioperativen Sektor integriert. Dabei ist der Nutzen dieser Technologien für relevante Endpunkte weitestgehend unklar. Diese sollten in gut-designten klinischen Studien rigoros getestet werden. Ärzte sollten diese technische Revolution aktiv mitgestalten, um das enorme Potenzial von AR und VR zum Wohle ihrer Patienten auszuschöpfen.
The Effect of Vitamin D Supplementation on Prostate Cancer: A Systematic Review and Meta-Analysis of Clinical Trials
Authors: Shahvazi Simin , Soltani Sepideh , Ahmadi Seyed , de Souza Russell , Salehi-Abargouei Amin
Published: December 2018

Vitamin D has received attention for its potential to disrupt cancer processes. However, its effect in the treatment of prostate cancer is controversial. This study aimed to assess the effect of vitamin D supplementation on patients with prostate cancer. In the present study, PubMed, Scopus, ISI Web of Science, and Google Scholar were searched up to September 2017 for trials that evaluated the effect of vitamin D supplementation on prostate specific antigen (PSA) response, mortality, and its possible side effects in participants with prostate cancer. The DerSimonian and Laird inverse-weighted random-effects model was used to pool the effect estimates. Twenty-two studies (16 before-after and 6 randomized controlled trials) were found and included in the meta-analysis. The analysis of controlled clinical trials revealed that PSA change from baseline [weighted mean difference (WMD)=–1.66 ng/ml, 95% CI: –0.69, 0.36, p=0.543)], PSA response proportion (RP=1.18, 95% CI: 0.97, 1.45, p=0.104) and mortality rate (risk ratio (RR)=1.05, 95% CI: 0.81–1.36; p=0.713) were not significantly different between vitamin D supplementation and placebo groups. Single arm trials revealed that vitamin D supplementation had a modest effect on PSA response proportion: 19% of those enrolled had at least a 50% reduction in PSA by the end of treatment (95% CI: 7% to 31%; p=0.002). Although before-after studies showed that vitamin D increases the PSA response proportion, it does not seem that patients with prostate cancer benefit from high dose vitamin D supplementation and it should not be recommended for the treatment.
Hypercortisolism in Newly Diagnosed Type 2 Diabetes: A Prospective Study of 384 Newly Diagnosed Patients
Authors: Steffensen Charlotte , Dekkers Olaf , Lyhne Johanne , Pedersen Bodil , Rasmussen Finn , Rungby Jørgen , Poulsen Per , Jørgensen Jens
Published: December 2018

Cross-sectional studies in small and selected populations report a high prevalence of hypercortisolism in patients with type 2 diabetes (T2D), which could have therapeutic implications, if confirmed. We therefore estimated the prevalence of hypercortisolism in a large and unselected cohort of recently diagnosed T2D patients. Consecutive patients with recently diagnosed T2D first underwent an overnight dexamethasone (1 mg) suppression test (OD). Patients not suppressing serum cortisol ≤50 nmol/l proceeded with a 48-h low dose dexamethasone suppression test (LDDST) and 24-h urinary free cortisol collection (UFC). Patients with elevated cortisol levels according to LDDST and/or UFC underwent imaging guided by plasma ACTH levels, and assessment of bone mineral density. A total of 384 T2D patients (232male/152 females) with a mean age of 60±10 years were included. Eighty-five (22%) patients suppressed incompletely to OD of whom 20 (5%) failed to suppress after LDDST and/or had elevated UFC (=hypercortisolism). Patients with hypercortisolism did not differ as regards age, BMI, HbA1c, T-score or blood pressure, but a higher proportion of them received antihypertensive treatment (100% vs. 64%, p=0.001). Imaging revealed adrenal adenoma(s) in 9 cases and a pituitary macroadenoma in 1 case. We found a 5% prevalence of hypercortisolism in unselected, recently diagnosed T2D, which was not associated with a persuasive cushingoid phenotype. The clinical implications are therefore uncertain.
Synthesis of the Deacetoxytubuvaline Fragment of Pretubulysin and its Lipophilic Analogues for Enhanced Permeability in Cancer Cell Lines
Authors: Chelvam Venkatesh , Reddy Ramesh , Dudhe Premansh
Published: December 2018

In the last two decades, tubulysins have emerged as alternatives to microtubule depolymerizing agents such as colchicine and vinblastine, which are well-established anticancer agents. However, the complex structure of tubulysins has always posed a challenge for synthetic chemists to scale up the production of these compounds. We report a new strategy for the practical gram-scale synthesis of a (4R)-4-[(tert-butoxycarbonyl)amino]-5-methylhexanoic acid through regioselective cleavage of a chiral aziridine ring with a vinyl Grignard reagent to afford tert-butyl [(1R)-1-isopropylbut-3-en-1-yl]carbamate, which was subjected to regioselective hydroboration–oxidation with 9-BBN. The resulting (4R)-4-[(tert-butoxycarbonyl)amino]-5-methylhexanoic acid was successfully transformed into the deacetoxytubuvaline fragment of pretubulysin or its highly lipophilic methyl-substituted thiazole and oxazole analogues for incorporation into pretubulysins. Increasing the lipophilicity of tubulysin or pretubulysin molecules should enhance their cell permeability and cytotoxicity in cancer cell lines.
Posttraumatic Headache
Authors: Dwyer Brigid
Published: December 2018

Posttraumatic headaches are among the most challenging complaints after mild traumatic brain injury (mTBI). They are a debilitating problem experienced by patients after TBI of all severities. Up to 90% of mild TBI patients experience headache, particularly if female and with a premorbid history of primary headache. Tension headache has classically been the most common subtype, but in military populations migraine has dominated. Posttraumatic headache encompasses a spectrum of headache types that overlap heavily with common primary headache disorders, but also autonomic cephalgias as well as several secondary headache conditions. It is important to understand the evolution of postconcussion syndrome as a concept, and the challenges associated with diagnosing and treating multidomain drivers effectively. The first-line treatments for posttraumatic headache are typically the same as those used in nontraumatic headache, with additional considerations for cognitive side effects, posttraumatic epilepsy, and coexisting injuries resulting in neuropathic pain or medication overuse.
Bioabsorbable Steroid Eluting Stents in the Treatment of Recurrent Rathke's Cleft Cyst
Authors: Ference Elisabeth H. , Badran Karam W. , Kuan Edward C. , Bergsneider Marvin , Heaney Anthony P. , Wang Marilene B.
Published: December 2018

Objectives Bioabsorbable steroid eluting stents may prevent the stenosis of ostia after sinus surgery. We describe a technique utilizing this technology to prevent the reformation of Rathke's cleft cysts (RCC) after transnasal transsphenoidal surgical drainage.

Design This study is based on retrospective review.

Setting The research took place at Tertiary academic medical center.

Participants Patients who underwent endoscopic marsupialization of RCC with stent placement were participated in this study.

Main Outcome Measures Demographics, surgical history, outcomes, and complications were primary measures of this study.

Results Four patients underwent drainage of a recurrent RCC with subsequent stent placement. All patients consented to off-label use of the stent. The mean age of patients was 42 years old and the number of prior drainage procedures ranged from 1 to 3. The stent was placed directly into the opening of the cyst after drainage with no other tissue placed into the cyst cavity or opening. The stents are bioabsorbable and were not removed after surgery but were evaluated endoscopically at 2 and 6 weeks after surgery. The patients have been followed for a mean of 14 months after surgery with no evidence of recurrence on endoscopic exam or imaging. No patient had cerebrospinal fluid leak during or after the operation or permanent endocrinopathy.

Conclusion The use of a bioabsorbable steroid eluting stent had no unanticipated consequences and all drainage pathways of all the RCCs remain patent. The use of this technology may decrease recurrence rates in revision or complex cases where patients have extensive scarring of the operative field from prior drainage procedures. Further follow-up of the current cases and study in a larger cohort are warranted.
Acute Ischemic Stroke: A Review of Imaging, Patient Selection, and Management in the Endovascular Era. Part II: Patient Selection, Endovascular Thrombectomy, and Postprocedure Management
Authors: Kumar G G Sharath , Nagesh Chinmay
Published: December 2018

Appropriate patient selection and expedient recanalization are the mainstay of modern management of acute ischemic stroke (AIS). Only a minority of patients (7–15%) of patients are eligible for endovascular therapy. Patient selection may be time based or perfusion based. Central to both paradigms is the selection of a patient with a small core, a significant penumbra that can be differentiated from areas of oligemia. A brief review of patient selection methods is presented. Endovascular thrombectomy techniques using stentrievers or aspiration catheters have now become the treatment of choice for AIS with large vessel occlusion. A range of devices, each with its own advantages and disadvantages, are available in the market for the neurointerventionist to choose. Techniques vary between devices and between operators, but standardization and protocolization are important within each center. Complications must be anticipated to be avoided. Once reperfusion is achieved, outcomes must be safeguarded with competent postprocedure management to prevent secondary brain injury. These aspects are reviewed in this article.
Proposal of energy efficiency policies for food and beverage industry in Brazil
Authors: Fabbriani Luiz , Calili Rodrigo
Published: December 2018

Energy efficiency can be seen as one of the best policies to be adopted by countries to reduce greenhouse gas emissions and for the contribution of the economy. Brazil, despite making some efforts aimed at the rational use of energy, is still far from being a protagonist in this area. On the other hand, countries such as Germany, Japan, and the United States have been adopting policies that aim to improve the use of energy and thus mitigate their greenhouse gas emissions, in addition to expanding the scope of business in this area. In order to achieve greater emphasis in the field of energy efficiency, the objective of this paper is to define energy efficiency policies for food and beverage industry based on international experiences and to measure their impacts in this industry. These policies are represented by technological diffusion curves and their impacts on the reduction of electricity consumption in the food and beverage industry are evaluated. There is a significant reduction in energy consumption and greenhouse gas emissions when adopting energy efficiency policies in this branch of industry, since energy efficiency policies provide an alternative to sustainable development.
Hydrogen oxidation kinetics on platinum-palladium bimetallic thin films for solid acid fuel cells
Authors: Paik Haemin , Berenov Andrey V. , Skinner Stephen J. , Haile Sossina M.
Published: December 2018

Solid acid fuel cells (SAFCs) based on the proton-conductive electrolyte CsH2PO4 have shown promising power densities at an intermediate operating temperature of ∼250 °C. However, Pt loadings in SAFCs remain higher than desirable, and the electrocatalysis mechanisms in these devices are still unknown. Here, hydrogen oxidation kinetics on Pt and Pt-Pd bimetallic thin film electrodes on CsH2PO4 have been evaluated to establish the potential for a beneficial role of Pd in SAFC anodes. Symmetric cells fabricated by depositing a metal film on both sides of electrolyte discs are characterized for studying hydrogen electro-oxidation across the gas|metal|CsH2PO4 structure. It was found that Pd reacts with CsH2PO4, forming palladium phosphide at the metal-electrolyte interface. Accordingly, the activity of Pd was examined in a bilayer geometry of Pd|Pt|CsH2PO4|Pt|Pd. The bilayer Pt|Pd films showed much higher activity for hydrogen electro-oxidation than films of Pt alone, as measured by AC impedance spectroscopy. Ex situ low energy ion scattering and scanning transmission electron microscopy revealed that Pd diffused into the Pt layer under operating conditions. The dramatic impact of Pd along with its presence throughout the film suggests that it catalyzes reactions at both the metal-gas and metal-electrolyte interfaces, as well as increasing hydrogen diffusion rates through the films.
Surface dominated magnetotransport in Bi2Te2.15Se0.85 topological insulator
Authors: Irfan Bushra , Dankert André , Bhasker Priyamvada , Khokhriakov Dmitrii , Dash Saroj P. , Chatterjee Ratnamala
Published: December 2018

Topological insulators (TIs) represent a new state of matter possessing an attractive surface spin texture with possible applications in quantum computation and spintronics. The growth of prototypical TIs such as Bi2Te3 and Bi2Se3 still remains a major challenge, because of vacancies and defects leading to an unintentional doping of the crystals creating a parallel conduction channel in the bulk. Here, we synthesized the Bi2Te2.15Se0.85 (BTS) TI using a modified Bridgeman technique. Magnetotransport studies at different angles and temperatures of the device made on thin (BTS) flakes reveal the 2D nature of the weak antilocalization signal and surface dominated transport properties at low temperatures.
Unsteady aerodynamic modeling and control of the wind turbine with trailing edge flap
Authors: Zhang Wenguang , Wang Yifeng , Liu Ruijie , Liu Haipeng , Zhang Xu
Published: December 2018

Intense load fluctuations on large-scale wind turbine blades can cause significant damage over time. The needs for predicting the dynamic behavior of blades and extending the lifespan of wind turbines have become more important. Therefore, in this paper, a wind turbine model with trailing edge flap (TEF) based on the National Renewable Energy Laboratory 5-MW reference wind turbine is developed, and a TEF controller aimed at load alleviation and power-fluctuation suppression is proposed. The wind turbine model, established in MATLAB/Simulink, consists of a TEF actuator model, an unsteady aerodynamic model, a generator model, and a drivetrain model. The TEF controller, which adopts a feedback linearization-based control method, is employed to reduce the variability of the flapwise root moment of blade 1 (FRM1) and the generator output power. Then, a comparison of the present model and a simulation of wind turbine performance with TEF control are demonstrated. Consequently, the present model shows reliability both in unsteady aerodynamic performance and wind turbine performance. In normal turbulent model wind conditions, the standard deviations of FRM1 and the generator output power are reported with reductions of 33.0%–42.5% and 9.1%–16.1%, respectively; the power spectral density of FRM1 is also reported with reductions of 39.9%–47.7%.
Reversible manipulation of lattice defects in single-crystal SnO2 microrod by applying mechanical stress and voltage
Authors: Sakurai Makoto , Liu Kewei , Aono Masakazu
Published: December 2018

We report a reversible transition between semiconducting and insulating states in a single-crystal SnO2 microrod device through creation and healing of lattice defects by applying mechanical stress and voltage. The process of creating lattice defects by using mechanical stress is investigated using transmission electron microscope and photoluminescence observations. The results reveal the presence of slip planes and non-volatile lattice defects. The healing process is analyzed through the dynamic response of the current to the pulse voltage applied to the ends of the microrod. It is found that there are fast and slow healing processes. The fast process is due to field-induced reduction of the trapping potential barrier, and the slow one is due to Joule heating. The reversible and nonlinear nature of the defect manipulation will open new avenues of innovation different from those of conventional technology, especially for the mechanical design of touch interfaces.
Impact of 100 keV proton irradiation on electronic and optical properties of AlGaN/GaN high electron mobility transistors (HEMTs)
Authors: Khanal Min P. , Uprety Sunil , Mirkhani Vahid , Wang Shiqiang , Yapabandara Kosala , Hassani Ehsan , Isaacs-Smith Tamara , Ahyi Ayayi C. , Bozack Michael J. , Oh Tae-Sik , Park Minseo
Published: December 2018

Proton irradiation-induced effects on AlGaN/GaN high electron mobility transistors (HEMTs) were studied by emulating a certain space radiation environment (upstream of the earth's bow shock) using a relatively low energy (100 keV) proton beam with fluences of 1 × 1010, 1 × 1012, and 1 × 1014 protons/cm2. In order to isolate radiation-induced effects produced by the modification of the epi-layer from the effects produced by the change in the device structure (such as contacts), the epi-layers were irradiated prior to device fabrication, followed by material/device characterization. Proton irradiation-induced sub-gap traps were detected by spectroscopic photo current-voltage measurement. Raman study revealed that the proton irradiation had induced strain relaxation on the AlGaN/GaN HEMTs epi-layer. No substantial change in the crystal quality of the epi-layer was indicated by Raman and PL studies. With increasing proton fluences, increasing charge carrier density was observed, which was estimated via Raman spectroscopy and the charge-control model analysis. The magnitude and direction of the transistor threshold voltage shift were also dependent on proton fluence. Overall, degradation of transistor output characteristics of the fabricated HEMTs was observed with increasing proton fluence. However, based on the observed performance and the level of influence on material/device characteristics by 100 keV protons, it can be suggested that the AlGaN/GaN HEMTs have high endurance for exposure to relatively high fluences of the low-energy proton beam.
Italian faire-infinitives
Authors: Schifano Norma , Sheehan Michelle
Published: December 2018

The first aim of this squib is to show that, under the correct syntactic configuration, volere ‘want’ can be embedded in Italian faire-infinitives (FI), contrary to previous claims. Secondly, we show that want-FIs exhibit peculiar properties: (i) they disallow a full DP causee; (ii) they permit intermediate cliticisation onto volere; (iii) they allow optional splitting of clitic clusters; and (iv) they marginally permit an accusative causee in transitive contexts where the object is a clitic. We attribute these effects to defective intervention which bans a full DP causee and requires the creation of a biclausal ECM construction, where accusative is exceptionally licensed, and where the selection of a silent OBTAIN by ‘want’ creates an additional clitic position.
Optional vs obligatory movement in Albanian (pseudo)-raising constructions
Authors: Turano Giuseppina
Published: December 2018

In this paper, I will analyse Albanian structures containing the verb duket ‘seem’. I will show that the raising analysis given for English cannot be extended to Albanian since, in English, raising is a last resort strategy that moves a subject from an infinitive clause to a matrix finite one, in order to be Case-marked. In Albanian, the verb duket selects a finite clause as its complement, so, NP-movement from the embedded clause to the matrix one is not obligatory, given that the NP originates in a position where Case is assigned/checked. Thus, in Albanian, the optional movement of the NP subject will be analysed both as Topicalization and sideward movement.
Diachronic and synchronic lexical interactions in the Italo-Balkan linguistic space
Authors: Altimari Francesco
Published: December 2018

This contribution presents a case study in the intricate diachronic and synchronic interrelations between languages in the Italian and Balkan linguistic spaces. Words related to Latin lucanica (‘type of sausage’) are investigated and hypotheses on their pattern of diffusion are surveyed and discussed. Among other points, the contribution touches on the etymology of lucanica itself, the intermediation role of Byzantine Greek, the multiple outcomes of the word in the Romanian group, its present-day distribution in Italo-Romance and Arbëresh dialects.
Lexical-semantic analysis of the political language
Authors: Desideri Paola
Published: December 2018

The aim of this paper is to provide an overview of the studies on political language produced between 1960 and 1980. This is a very important period for research in this area, as it marks a significant development of lexical-semantic analysis concerning linguistic corpora, which are essential to the history of Europe. The speeches by the protagonists of the French Revolution, the totalitarian languages, the messages by last century parties and leaders, as well as the dictionaries and different political lexicon adopted by East and West Germany are notably the favoured subjects for semantic in-depth analysis, to understand the significant connotations and meaning effects.
Apparent temperature: demystifying the relation between quantum coherence, correlations, and heat flows
Authors: Latune C L , Sinayskiy I , Petruccione F
Published: December 2018

Heat exchanges are the essence of Thermodynamics. In order to investigate non-equilibrium effects like quantum coherence and correlations in heat flows we introduce the concept of apparent temperature. Its definition is based on the expression of the heat flow between out-of-equilibrium quantum systems. Such apparent temperatures contain crucial information on the role and impact of correlations and coherence in heat exchanges. In particular, both behave as populations, affecting dramatically the population balance and therefore the apparent temperatures and the heat flows. We show how seminal results can be re-obtained, offering an interesting alternative point of view. We also present new predictions and suggest a simple experiment to test them. Our results show how quantum and non-equilibrium effects can be used advantageously, finding applications in quantum thermal machine designs and non-equilibrium thermodynamics but also in collective-effect phenomena.
Collecting wild Miscanthus germplasm in Asia for crop improvement and conservation in Europe whilst adhering to the guidelines of the United Nations’ Convention on Biological Diversity
Authors: Huang Lin S , Flavell Richard , Donnison Iain S , Chiang Yu-Chung , Hastings Astley , Hayes Charlotte , Heidt Chris , Hong Hao , Hsu Tsai-Wen , Humphreys Mervyn , Jackson Julian , Norris John , Schwarz Kai-Uwe , Squance Michael , Swaller Timothy , Thomas Ian David , Van Assche Wilfriede , Xi Qingguo , Yamada Toshihiko , Youell Sue , Clifton-Brown John
Published: December 2018

Background and Aims

Germplasm with diverse, agronomically relevant traits forms the foundation of a successful plant breeding programme. Since 1993, the United Nations has been advocating the implementation of the Convention on Biological Diversity (CBD) and the subsequent 2002 Bonn Guidelines as international best practice on germplasm collection and use. In 2006, a European team made an expedition to Asia to collect wild germplasm of Miscanthus, a C4 perennial rhizomatous grass, for breeding an environmentally adaptable, resilient and high-yielding bioenergy crop. We outline general aspects of germplasm collection, conservation, breeding and biomass production evaluation while following the CBD’s guidelines, respecting biodiversity and conservation needs, and the ethical use of genetic resources.

Methods

Effective protocols, quarantine, methods for collecting seed and rhizomes, and a genebank for conservation were established. Versatile informatics and database architecture were used to assist in selection, flowering synchronization, crossing, evaluation, phenotyping and data integration. Approaches were formulated to comply with the CBD guidelines.

Key Results

A total of 303 accessions of M. sinensis, M. sacchariflorus and M. floridulus were collected from 158 geographically and environmentally diverse locations. These species were shown to accumulate different amounts of aerial biomass due to combinations of stem count, height and thickness. Progeny from one interspecies cross accumulated more biomass in early trials and has shown double the yield performance in years 3–4 compared with the existing commercial cultivar M. × giganteus. An example of an F1 hybrid has already demonstrated the long-term potential of exploiting this collection for a breeding programme.

Conclusions

By conforming to the CBD principles, the authors’ international collaboration provides a practical example of implementing the CBD. The collection widened the genetic diversity of Miscanthus available to allow for breeding of novel hybrids that exhibit more diverse traits to increase yield and resilience for growth on marginal land and in climate-challenged environments.
A novel measure of non-coding genome conservation identifies genomic regulatory blocks within primates
Authors: Nash Alexander J , Lenhard Boris
Published: December 2018

Motivation

Clusters of extremely conserved non-coding elements (CNEs) mark genomic regions devoted to cis-regulation of key developmental genes in Metazoa. We have recently shown that their span coincides with that of topologically associating domains (TADs), making them useful for estimating conserved TAD boundaries in the absence of Hi-C data. The standard approach—detecting CNEs in genome alignments and then establishing the boundaries of their clusters—requires tuning of several parameters and breaks down when comparing closely related genomes.

Results

We present a novel, kurtosis-based measure of pairwise non-coding conservation that requires no pre-set thresholds for conservation level and length of CNEs. We show that it performs robustly across a large span of evolutionary distances, including across the closely related genomes of primates for which standard approaches fail. The method is straightforward to implement and enables detection and comparison of clusters of CNEs and estimation of underlying TADs across a vastly increased range of Metazoan genomes.

Availability and implementation

The data generated for this study, and the scripts used to generate the data, can be found at https://github.com/alexander-nash/kurtosis_conservation.

Supplementary information

Supplementary data are available at Bioinformatics online.