bluuebunny/crossref_metadata_2025 huggingface dataset:
The School-Based Speech-Language Pathologist's Role in Diverting the School-to-Confinement Pipeline for Youth With Communication Disorders
Authors: Stanford Shameka
Published: August 2020

Purpose

The overarching aim of this article is to discuss the intersectionality of the school-to-confinement pipeline and its detrimental effect on the societal and academic success of youth with communication disorders. Communication disorders in youth with behavior concerns or placed at risk for delinquency that is not adequately addressed by a speech-language pathologist (SLP) can increase the youth's involvement with the school-to-confinement pipeline, resulting in a dire need for the intervention of the SLP to intervene on the language-based needs of this population. However, the role of the United States—based SLPs in interrupting the school-to-confinement pipeline has not yet been clearly defined and recognized.

Method

This article will (a) discuss why the role of the SLP providing language intervention for youth placed at risk for delinquency or involved with the criminal justice system is necessary, (b) discuss the definition of the school-to-confinement pipeline, (c) examine the impact of the school-to-confinement pipeline on youth with communication disorders, and (d) highlight a framework for cognitive and language-based intervention that may promote positive outcomes.

Results

The SLP's role in interrupting the school-to-confinement pipeline is vital to providing and increasing the societal and academic success of youth with communication disorders placed at risk for delinquency and should consider multiple factors such as (a) SLPs becoming an active and integral member of the individualized education plan team, (b) SLPs advocating for opportunities to collaborate and interact with the youth as an integral member of the individualized education plan team, and (c) SLPs creating consistent and streamlined opportunities for culturally relevant goals and intervention that increase the student's academic and societal success.

Conclusion

There are many reasons why the SLPs' role in interrupting the school-to-confinement pipeline cannot be ignored or overlooked. As a profession in the United States, speech-language pathology is in the early stages of developing a stronger stance for advocacy and understanding the communication needs of youth on the SLP's caseload who are at risk for the school-to-confinement pipeline. Nonetheless, increasing how SLPs approach and intervene on behalf of students with communication disorders may produce better outcomes for youth-at-risk for the school-to-confinement pipeline.
A Cross-Sectional Study of the Portrayal of Vocal Health in YouTube Videos
Authors: Bellon-Harn Monica L. , Ulep Alyssa J. , Dueppen Abigail , Manchaiah Vinaya , Ravi Rohit , Gunjawate Dhanshree R.
Published: August 2020

Purpose

The current study examines metadata, upload source, type of informational content, understandability, and actionability of YouTube videos related to vocal health.

Method

A search for videos related to vocal health in YouTube was completed. Metadata (i.e., number of views, video length, thumbs-up, thumbs-down), upload source (i.e., consumer, professional, media), and type of informational content were identified. The Patient Education Material Assessment Tool for Audiovisual Materials was used to assess understandability and actionability of the 100 most frequently viewed videos.

Results

A total of 166 videos were obtained. The collective number of views was 19,799,299. A significant difference between video source groups was found for number of views and thumbs-down, but not for video length or thumbs-up. The YouTube videos were primarily educational, and a majority of the content focused on tips and techniques for professional voice users. Videos had adequate understandability (i.e., 71.5%) and actionability scores (i.e., 74%). Videos uploaded by consumers were superior to professional sources in actionability, but no difference was noted between video source for understandability.

Conclusions

Study insights about metadata, source, type of informational content, understandability, and actionability of YouTube videos may help professionals understand the nature of online content related to vocal health. Study implications and recommendations for further research are discussed.
Collisions between amorphous carbon nanoparticles: phase transformations
Authors: Nietiadi Maureen L. , Valencia Felipe , Gonzalez Rafael I. , Bringa Eduardo M. , Urbassek Herbert M.
Published: August 2020

Context. Collisions of nanoparticles (NPs) occur in dust clouds and protoplanetary disks.

Aims. Sticking collisions lead to the growth of NPs, in contrast to bouncing or even fragmentation events and we aim to explore these processes in amorphous carbon NPs.

Methods. Using molecular-dynamics simulations, we studied central collisions between amorphous carbon NPs that had radii in the range of 6.5–20 nm and velocities of 100–3000 m s−1, and with varying sp3 content (20–55%).

Results. We find that the collisions are always sticking. The contact radius formed surpasses the estimate provided by the traditional Johnson-Kendall-Roberts model, pointing at the dominant influence of attractive forces between the NPs. Plasticity occurs via shear-transformation zones. In addition, we find bond rearrangements in the collision zone. Low-sp3 material (sp3 ≤ 40%) is compressed to sp3 > 50%. On the other hand, for the highest sp3 fraction, 55%, graphitization starts in the collision zone leading to low-density and even porous material.

Conclusions. Collisions of amorphous carbon NPs lead to an increased porosity, atomic surface roughness, and changed hybridization that affect the mechanical and optical properties of the collided NPs.
Response of advanced HCC to pembrolizumab and lenvatinib combination therapy despite monotherapy failure
Authors: Schulte Nadine , Li Moying , Zhan Tianzuo , Dreikhausen Lena , Sollors Janina , Antoni Christoph , Diehl Steffen , Schoenberg Stefan O. , Rahbari Nuh , Reissfelder Christoph , Giordano Frank A. , Ebert Matthias P. , Teufel Andreas
Published: August 2020

In recent years, immune checkpoint inhibitors (ICIs) were successfully introduced to cancer therapy, and these drugs have already become essential for the treatment of various noncurable tumors. However, monotherapy in advanced hepatocellular carcinoma (aHCC) failed to show statistically significant improvement.

Recently, the combination of atezolizumab and bevacizumab demonstrated efficacy of combining ICI and VEGF inhibition, further substantiating previous data on synergistic mechanisms among respective substance classes.

As TKI treatment is currently standard of care for aHCC, and ICIs are approved by the FDA and available in many areas of the world, numerous patients may have been treated with monotherapy of those drugs. However, it remains unclear if failure to monotherapy has an impact on combination therapy. We therefore report a patient well responding to combination therapy despite previous failures to TKI and ICI monotherapy.
Nährstoffe – Power für das Immunsystem
Authors: Schmiedel Volker
Published: August 2020

Wir kennen ca. 50 essenzielle Nährstoffe (wir können es nicht ganz sicher angeben, da beispielsweise einige Aminosäuren nur semi-essenziell sind und bei einigen Nährstoffen die Essenzialität nur diskutiert wird, aber keineswegs gesichert ist). Bei einigen von ihnen gilt es als gesichert, dass sie zur Funktion des Immunsystems enorm beitragen bzw. ein Mangel auch eine Minderfunktion des Immunsystems zur Folge hat. Das Erstaunliche daran: Manche Nährstoffe wirken nicht nur stimulierend, sondern modulierend – ein schwaches Immunsystem wird gefördert, ein überschießendes Immunsystem, wie wir es z. B. bei Autoimmunkrankheiten oder Allergien beobachten, wird hingegen herunterreguliert.
Schlaf stärkt das Immunsystem
Authors: Heinzlmeier Alexander
Published: August 2020

Es existiert eine Vielzahl von Ursachen, die zu Schlafmangel führen können. Dazu zählen u. a. Schichtarbeit, beruflicher und privater Stress, Sorgen, Ängste oder viel Zeit, die vor PC- und Fernsehbildschirmen verbracht wird. Schlafstörungen und der resultierende Schlafmangel beeinträchtigen nicht nur das Befinden und die Leistungsfähigkeit, sondern können auch Erkrankungen begünstigen wie erhöhte Infektanfälligkeit, Herz-Kreislauf-Erkrankungen, Diabetes Typ 2 bis hin zu Krebserkrankungen. Immer mehr Studien belegen, dass insbesondere das Immunsystem für seine Funktionsfähigkeit auf regelmäßigen und erholsamen Schlaf angewiesen ist.
Komplikationsmanagement bei der TUR-Blase
Authors: Mally David , Paffenholz Pia
Published: August 2020

Die transurethrale Resektion der Harnblase (TUR-Blase) ist ein Standardeingriff der operativen Urologie. Eine komplette Resektion steht hierbei an höchster Stelle. Darüber hinaus ist die Kenntnis der möglichen Komplikationen und das dazugehörige Komplikationsmanagement für die klinische Praxis essenziell. Zu den häufigsten Komplikationen gehören katheterassoziierte Beschwerden, Blutungen, Infektionen und die Harnblasenperforation. Doch auch die Resektion des Harnleiterostiums und Lagerungsschäden stellen zwar seltenere, aber dennoch unmittelbar behandlungswürdige Komplikationen dar. In der vorliegenden Übersichtsarbeit werden diese Komplikationen zusammengefasst sowie deren Vorbeugung und Management vorgestellt.
Neodymium-Promoted Highly Selective Carbon–Carbon Double Bond Formation of Ketones with Allyl Halides in the Presence of Diethyl Phosphite
Authors: Zhang Songlin , Xie Dengbing , Wang Yiqiong , Yang Bo
Published: August 2020

The carbon–carbon double bond formation via neodymium-mediated Barbier-type reaction of ketones and allyl halides in the presence of diethyl phosphite is reported for the first time. The reaction is highly α-regioselective and was conveniently carried out under mild conditions in a one-pot fashion. From a synthetic point of view, a series of conjugated alkenes were obtained in moderate to good yields in this one-pot reaction with feasible reaction conditions.
Monsters at bedtime: managing fear in bedtime picture books for children
Authors: Maynes Mary-Louise
Published: August 2020

Monsters make frequent appearances in bedtime stories for children, where they represent a range of common childhood fears, in particular those associated with night-time. In this article, the role and nature of ‘bedtime’ monsters is explored with reference to picture book examples from 20th to 21st century children’s literature. The ways in which they help children to manage fears are shown to be through a combination of both psychological and literary strategies, drawing on examples of English language picture books for children aged 2–5 years, but with a particular focus on three contemporary texts: Molly and the Night Monster; Bedtime for Monsters and The Wardrobe Monster. It is argued that these texts often mirror coping strategies preferred by young children, in particular positive pretence, where threats are minimised or eliminated by mentally changing or altering perception of them. However, in addition to positive pretence, fears are further managed by literary and visual devices employed by the picture book creator/s, in particular in the presentation of images. The article concludes by noting that this is a group of texts which is now sufficiently established to be open to self-reference and parody, and consequently new and playful variations on the bedtime monster story will continue to emerge and evolve.
Ultra-sensitive refractive index gas sensor with functionalized silicon nitride photonic circuits
Authors: Antonacci Giuseppe , Goyvaerts Jeroen , Zhao Haolan , Baumgartner Bettina , Lendl Bernhard , Baets Roel
Published: August 2020

Portable and cost-effective gas sensors are gaining demand for a number of environmental, biomedical, and industrial applications, yet current devices are confined into specialized labs and cannot be extended to general use. Here, we demonstrate a part-per-billion-sensitive refractive index gas sensor on a photonic chip based on silicon nitride waveguides functionalized with a mesoporous silica top-cladding layer. Low-concentration chemical vapors are detected by monitoring the output spectral pattern of an integrated unbalanced Mach-Zehnder interferometer having one coated arm exposed to the gas vapors. We retrieved a limit of detection of 65 ppb, 247 ppb, and 1.6 ppb for acetone, isopropyl alcohol, and ethanol, respectively. Our on-chip refractive index sensor provides, to the best of our knowledge, an unprecedented limit of detection for low gas concentrations based on photonic integrated circuits. As such, our results herald the implementation of compact, portable, and inexpensive devices for on-site and real-time environmental monitoring and medical diagnostics.
Deriving the vibronic coupling constants of the cyclopentadienyl radical with density functional theory and G
W
Authors: Wong Zi Cheng , Ungur Liviu
Published: August 2020

The vibronic coupling constants of the cyclopentadienyl radical have been calculated with G0W0, HF, and density functional theory (DFT) with various exchange-correlation functionals such as PBE, PBE0, LC-ωPBE, and the non-empirically tuned LC-ωPBE*. The vibronic coupling constants for HF and DFT were derived using the gradients of the eigenvalues of the degenerate HOMOs of the closed-shell cyclopentadienyl anion, while the gradients of the corresponding quasiparticle energy levels were used in the case of G0W0. The differences between the linear vibronic constants obtained using HF and DFT were found to be small and reduced further when the G0W0 correction is applied to HF and DFT. Finally, the linear vibronic coupling constants calculated with G0W0 were found to agree well with the values obtained using high level wave function methods in the literature, which suggests that G0W0 can be a useful tool toward the study of vibronic coupling.
Estimating the genome-wide contribution of selection to temporal allele frequency change
Authors: Buffalo Vince , Coop Graham
Published: August 2020

Significance

A long-standing problem in evolutionary biology is to understand the processes that shape the genetic composition of populations. In a population without migration, two processes that change allele frequencies are selection, which increases beneficial alleles and removes deleterious ones, and genetic drift, which randomly changes frequencies as some parents contribute more or fewer alleles to the next generation. Previous efforts to disentangle these processes have used genomic samples from a single time point and models of how selection affects neighboring sites (linked selection). Here, we use genomic data taken through time to quantify contributions of selection and drift to genome-wide frequency changes. We show that selection acts over short timescales in three evolve-and-resequence studies and has a sizable genome-wide impact.
From one cell to many: Morphogenetic field of lateral root founder cells in
Arabidopsis thaliana
is built by gradual recruitment
Authors: Torres-Martínez Héctor H. , Hernández-Herrera Paul , Corkidi Gabriel , Dubrovsky Joseph G.
Published: August 2020

Significance

A single plant can produce from hundreds to millions of lateral roots (LRs), which facilitate water and mineral uptake and transport. LRs originate in a tissue called the pericycle, but the underlying mechanism is obscure. With the aid of clonal analysis, we deduced that LR initiation begins with a single pericycle founder cell (FC) which then recruits the neighboring pericycle cells to become FCs. A time-lapse analysis validated this conclusion and also showed that FC recruitment is an auxin-dependent and gradual process that takes place in an unpredictable pattern. Thus, LR initiation is not a one-step process, as previously considered.
Effect of shoe cushioning on landing impact forces and spatiotemporal parameters during running: results from a randomized trial including 800+ recreational runners
Authors: Malisoux Laurent , Delattre Nicolas , Meyer Christophe , Gette Paul , Urhausen Axel , Theisen Daniel
Published: August 2020

In a recent randomized trial including 800+ recreational runners, injury risk was lower in those who received the Soft shoe version compared to those using the Hard version (Hazard ratio = 1.52; 95% Confidence Interval = 1.07–2.16). Here, we investigated the effect of shoe cushioning on ground reaction forces (GRF) and spatiotemporal parameters in the same cohort, with a special focus on Vertical Impact Peak Force (VIPF) and Vertical Instantaneous Loading Rate (VILR). Healthy runners (n = 848) randomly received one of two shoe prototypes that differed only in their cushioning properties (Global stiffness: 61 ± 3 and 95 ± 6 N/mm in the Soft and Hard versions, respectively). Participants were tested on an instrumented treadmill at their preferred running speed. GRF data was recorded over 2 min. VIPF was higher in the Soft shoe group compared to the Hard shoe group (1.53 ± 0.21 vs. 1.44 ± 0.23 BW, respectively; p < 0.001). However, the proportion of steps with detectable VIPF was lower in the Soft shoe group (84 vs. 97%, respectively; p < 0.001) and Time to VIPF was longer (46.9 ± 8.5 vs. 43.4 ± 7.4 milliseconds, respectively; p < 0.001). No significant differences were observed for VILR (60.1 ± 13.8 vs. 58.9 ± 15.6 BW/s for Soft and Hard shoe group, respectively; p = 0.070) or any other kinetic variable. These results show that the beneficial effect of greater shoe cushioning on injury risk in the present cohort is not associated with attenuated VIPF and VILR. These GRF metrics may be inappropriate markers of the shoe cushioning‐injury risk relationship, while delayed VIPF and the proportion of steps displaying a VIPF could be more relevant.

Trial registration: ClinicalTrials.gov identifier: NCT03115437.
Challenging precarity, austerity and delocalisation: Italian labour struggles from Euro-criticism to Euro-disenchantment
Authors: Zamponi Lorenzo
Published: August 2020

How has the experience of crisis, austerity, and precarity affected visions of Europe in the labour movement? The article answers this question through the analysis of interviews of representatives of organisations engaged in labour struggles in Italy and of documents published by the same organisations. The analysis shows that, although the crisis has challenged ‘critical Europeanism’ and radicalised vision of Europe, the border between calls for ‘another Europe’ and Eurosceptic claims seems resilient: Euro-criticism is in crisis, but has left more ground to a frustrated Euro-disenchantment than to Euro-scepticism. At the theoretical level, these findings contribute to the literature on strategic adaptation, pointing out that the reaction of movements to the closing of opportunities is far from automatic. Regarding the evolution of the Italian civil society, the shift towards Euroscepticism reflects the utter lack of hope towards the EU as a force of progress determined by a decade of austerity.
A fully quantum calculation of broadening and shifting coefficients of the D1 and D2 spectral lines of alkali-metal atoms colliding with noble-gas atoms
Authors: Loper Robert D , Weeks David E
Published: August 2020

We use the Baranger model to compute collisional broadening and shift rates for the D
1 and D
2 spectral lines of M + Ng, where M = K, Rb, Cs and Ng = He, Ne, Ar. Scattering matrix elements are calculated using the channel packet method, and non-adiabatic wavepacket dynamics are determined using the split-operator method together with a unitary transformation between adiabatic and diabatic representations. Scattering phase shift differences are weighted thermally and are integrated over temperatures ranging from 100 K to 800 K. We find that predicted broadening rates compare well with experiment, but shift rates are predicted poorly by this model because they are extremely sensitive to the near-asymptotic behavior of the potential energy surfaces.
Role of residual interaction in the relativistic description of M1 excitation
Authors: Oishi Tomohiro , Kružić Goran , Paar Nils
Published: August 2020

Magnetic dipole (M1) excitation is the leading mode of multi-nucleon excitations induced by the magnetic field, and is a phenomenon of the spin–orbit splitting and residual interactions involved. In this work, we investigate the effects of the residual interactions on the M1 excitation from a novel perspective, the framework of relativistic nuclear energy-density functional. The relativistic Hartree–Bogoliubov model is utilized to determine the nuclear ground state properties, while the relativistic quasi-particle random-phase approximation is employed for the description of M1-excitation properties. From the analysis of M1 mode in the Ca isotope chain, role of the isovector–pseudovector residual interaction is discussed. For open-shell nuclei, the pairing correlation also plays a noticeable role in the M1 mode. The experimental data on M1 mode is expected to provide a suitable reference to improve and optimize the theoretical models to describe the residual interactions.
Pressure-induced isostructural electronic topological transitions in 2H-MoTe2: x-ray diffraction and first-principles study
Authors: Bera Achintya , Singh Anjali , Gupta Satyendra Nath , Glazyrin K , Muthu D V S , Waghmare U V , Sood A K
Published: August 2020

Synchrotron x-ray diffraction measurements on powder 2H-MoTe2 (P63/mmc) up to ∼46 GPa have been performed along with first-principles based density functional theoretical analysis to probe the isostructural transition in low pressure regime and two electronic topological transitions (ETT) of Lifshitz-type in high pressure regime. The low pressure isostructural transition at ∼7 GPa is associated with the lattice parameter ratio c/a anomaly and the change in the compressibility of individual layers. The pressure dependence of the volume by linearizing the Birch–Murnaghan equation of state as a function of Eulerian strain shows a clear change of the bulk modulus at the ETT pressure of ∼20 GPa. The minimum of c/a ratio around 32 GPa is associated with the change in topology of electron pockets marked as second ETT of Lifshitz-type. We do not observe any structural transition up to the maximum applied pressure of ∼46 GPa under quasi-hydrostatic condition.
Electromagnetic force compensation weighing cell with magnetic springs and air bearings
Authors: Yoon Kyung-Taek , Park Sung-Ryong , Choi Young-Man
Published: August 2020

The electromagnetic force compensation (EMFC) principle is a state-of-the-art weighing method for precision mass measurement. In this method, the low stiffness of the flexure-based Roberval guide mechanism and high lever ratio of force transmission contribute to achieving extremely high weighing sensitivity. However, weak damping and the parasitic resonant frequencies of the flexure mechanism lead to a slow settling time after loading a weight. Moreover, the low ruggedness of the flexure mechanism limits the load capacity of the EMFC weighing cell and may result in fatigue failure under repeated loading. In this paper, we propose a novel precision weighing cell with Halbach array magnetic springs and air bearings instead of the flexure mechanism. The magnetic spring is designed for near-zero negative stiffness to increase the system bandwidth, as well as for gravity force compensation ability against deadweights. The air bearings ensure high ruggedness toward parasitic directions with high stiffness in the parasitic direction and a damping effect from the pressurized air film. The stiffness of the fabricated prototype weighing cell is −27.3 N m−1, which is tens of times lower than that of conventional EMFC weighing cells. The weighing repeatability of the weighing cell is 2.35 mg, as measured with a 10 g E2 class test mass, and the settling time within ±2% of its final value is 57 ms in air.
Robust image segmentation for feature extraction from internal combustion engine in-cylinder images
Authors: Rochussen Jeremy , Kirchen Patrick
Published: August 2020

In-cylinder imaging diagnostics for internal combustion engines provide rich information on the structure and evolution of reaction zone features, which affect both engine out emissions and efficiency. However, the most common analysis of in-cylinder combustion luminosity imaging considers ensemble averaged images, which are not suitable for characterizing processes that vary significantly between cycles, such as ignition and soot formation and oxidation. Here, a robust image segmentation algorithm is presented for feature extraction from single-cycle in-cylinder combustion images and is used with a ‘combination of interpretations’ (COI) approach to analyze OH*-chemiluminescence imaging of premixed and non-premixed natural gas combustion modes in an optically-accessible reciprocating engine.

Dynamic thresholding and region size filtering are combined with watershed segmentation to create a parameterized adaptive watershed (PAW) segmentation algorithm. The fusion of these segmentation methods is novel to combustion imaging and is demonstrated to provide quantified improvement relative to the current state of the art segmentation methods; PAW segmentation provides increased sensitivity for early ignition processes, and more robustly identifies the reaction zones at later stages of combustion. The PAW algorithm requires no adjustment between the two considered combustion modes or for any stage of the combustion process. The reliability of the PAW output enables feature extraction of individual reaction zone location and area from the combustion images using a polar-sector coordinate system for COI analysis. This approach characterizes the cyclic variability of individual fuel jets, identifies coupling of auto-ignition behavior between adjacent reaction zones, and demonstrates systematic errors arising from measurement of auto-ignition in ensemble averaged images. Application of PAW segmentation and the analysis approach presented here can provide more complete characterization of other spatially-resolved internal combustion diagnostics, particularly where there is high process variability, overlapping image regions, or wide signal intensity ranges.
Earth abundant transition metal ferrite nanoparticles anchored ZnO nanorods as efficient and stable photoanodes for solar water splitting
Authors: Maity Dipanjan , Karmakar Keshab , Mandal Dipika , Pal Debashish , Khan Gobinda Gopal , Mandal Kalyan
Published: August 2020

Poor light absorption, severe surface charge recombination and fast degradation are the key challenges with ZnO nanostructures based electrodes for photoelectrochemical (PEC) water splitting. Here, this study attempts to design an efficient and durable nano-heterojunction photoelectrode by integrating earth abundant chemically stable transition metal spinel ferrites MFe2O4 (M = Co and Ni) nano-particles on ZnO Nanorod arrays. The low band gap magnetic ferrites improve the solar energy harvesting ability of the nano-heterojunction electrodes in ultraviolet–visible light region resulting in a maximum increase of 105% and 190% in photocurrent density and applied bias photon-to-current efficiency, respectively, compared to pristine ZnO nanorods. The favourable type-II band alignment at the ferrites/ZnO nano-heterojunction provides significantly enhanced photo-generated carrier separation and transfer, endowing the excellent solar H2 evolution ability (743 and 891 μmol cm−2 h−1for ZnO/CoFe2O4 and ZnO/NiFe2O4, respectively) of the photoanodes by using sacrificial agent. The hybrid nanostructures deliver long term stability of the electrode against photocorrosion. This work demonstrates an easy but effective strategy to develop low-cost earth abundant ferrites-based heterojunction electrodes, which offers excellent PEC activity and stability.
Polaroid-PET: a PET scanner with detectors fitted with Polaroid for filtering unpolarized optical photons—a Monte Carlo simulation study
Authors: Sanaat Amirhossein , Ashrafi-Belgabad Aydin , Zaidi Habib
Published: August 2020

We propose and evaluate the performance of an improved preclinical positron emission tomography (PET) scanner design, referred to as Polaroid-PET, consisting of a detector equipped with a layer of horizontal Polaroid to filter scintillation photons with vertical polarization. This makes it possible to improve the spatial resolution of PET scanners based on monolithic crystals. First, a detector module based on a lutetium-yttrium orthosilicate monolithic crystal with 10 mm thickness and silicon photomultipliers (SiPMs) was implemented in the GEANT4 Monte Carlo toolkit. Subsequently, a layer of Polaroid was inserted between the crystal and the SiPMs. Two preclinical PET scanners based on ten detector modules with and without Polaroid were simulated. The performance of the proposed detector modules and corresponding PET scanner for the two configurations (with and without Polaroid) was assessed using standard performance parameters, including spatial resolution, sensitivity, optical photon ratio detected for positioning, and image quality. The detector module fitted with Polaroid led to higher spatial resolution (1.05 mm FWHM) in comparison with a detector without Polaroid (1.30 mm FHWM) for a point source located at the center of the detector module. From 100% of optical photons produced in the scintillator crystal, 65% and 66% were used for positioning in the detectors without and with Polaroid, respectively. Polaroid-PET resulted in higher axial spatial resolution (0.83 mm FWHM) compared to the scanner without Polaroid (1.01 mm FWHM) for a point source at the center of the field of view (CFOV). The absolute sensitivity at the CFOV was 4.37% and 4.31% for regular and Polaroid-PET, respectively. Planar images of a grid phantom demonstrated the potential of the detector with a Polaroid in distinguishing point sources located at close distances. Our results indicated that Polaroid-PET may improve spatial resolution by filtering the reflected optical photons according to their polarization state, while retaining the high sensitivity expected with monolithic crystal detector blocks.
GPU-accelerated Monte Carlo simulation of MV-CBCT
Authors: Shi Mengying , Myronakis Marios , Jacobson Matthew , Ferguson Dianne , Williams Christopher , Lehmann Mathias , Baturin Paul , Huber Pascal , Fueglistaller Rony , Lozano Ingrid Valencia , Harris Thomas , Morf Daniel , Berbeco Ross I
Published: August 2020

Monte Carlo simulation (MCS) is one of the most accurate computation methods for dose calculation and image formation in radiation therapy. However, the high computational complexity and long execution time of MCS limits its broad use. In this paper, we present a novel strategy to accelerate MCS using a graphic processing unit (GPU), and we demonstrate the application in mega-voltage (MV) cone-beam computed tomography (CBCT) simulation. A new framework that generates a series of MV projections from a single simulation run is designed specifically for MV-CBCT acquisition. A Geant4-based GPU code for photon simulation is incorporated into the framework for the simulation of photon transport through a phantom volume. The FastEPID method, which accelerates the simulation of MV images, is modified and integrated into the framework. The proposed GPU-based simulation strategy was tested for its accuracy and efficiency in a Catphan 604 phantom and an anthropomorphic pelvis phantom with beam energies at 2.5 MV, 6 MV, and 6 MV FFF. In all cases, the proposed GPU-based simulation demonstrated great simulation accuracy and excellent agreement with measurement and CPU-based simulation in terms of reconstructed image qualities. The MV-CBCT simulation was accelerated by factors of roughly 900–2300 using an NVIDIA Tesla V100 GPU card against a 2.5 GHz AMD Opteron™ Processor 6380.
Kinetic modelling of parallel ion transport in the scrape-off layer and divertor of inter-edge localised mode JET high radiative H-mode plasma
Authors: Chankin A V , Corrigan G , Jaervinen A E
Published: August 2020

KInetic code for Plasma Periphery (KIPP) was used to assess the importance of kinetic effects of parallel ion transport in the scrape-off layer (SOL) and divertor of JET high radiative H-mode inter-edge localised mode plasma conditions with strong nitrogen (N2) injection, leading to partial detachment at divertor targets. Plasma parameter profiles along the magnetic field from one of the EDGE2D-EIRENE simulation cases were used as an input for KIPP runs. The profiles were maintained by particle and power sources. This work is a continuation of the previous study carried out for electrons (Chankin et al 2018 Plasma Phys. Control. Fusion
60 115011).

In this modelling KIPP calculated ion distribution functions and ion parallel power fluxes. In the main SOL kinetic effects lead to a reduction of heat (conductive power) fluxes compared to Braginskii fluxes by factors 3−4 (‘heat flux limiting’). In the divertor, on the contrary, a strong ‘heat flux enhancement’, by up to two orders of magnitude above Braginskii’s, was found. Similar to cases for electrons, high ion heat flux enhancement factors, in particular near targets, are attributed to a non-local transport of super-thermal ions originating from positions along field lines with the highest ion temperature, resulting in the appearance of bump-on-tail features on ion heat flux density profiles. Despite ion heat flux enhancement factors at the target being much higher than for electrons, total power fluxes, ion plus electron, were dominated by ion and electron convection and electron conduction, with ion conductive fluxes playing a secondary role. This must be attributed to lower ion (than electron) velocities (factor ∼

m
e

/

m
i

reduction), which are not compensated by kinetic effects of lower ion upstream collisionality.
Effect of varying N2 pressure on DC arc plasma properties and microstructure of TiAlN coatings
Authors: Syed B , Hsu T-W , Chaar A B B , Polcik P , Kolozsvari S , Håkansson G , Rosen J , Johnson L J S , Zhirkov I , Andersson J M , Jöesaar M J , Odén M
Published: August 2020

Detailed knowledge of correlations between direct current (DC) cathodic arc deposition process parameters, plasma properties, and the microstructure of deposited coatings are essential for a comprehensive understanding of the DC cathodic arc deposition process. In this study we have probed the plasma, generated by DC arc on a Ti-50 at.% Al cathode in a N2 ambience, at the growth front of the TiAlN coating. Several consequences of an increasing N2 pressure are observed, including a decreased electron temperature, an increased electron density, and a loss of energetic ions. As a result, the preferred growth texture switches from 220 to 111. It is also observed that neutrals in the plasma can significantly contribute to the growth of TiAlN coatings.
Theoretical and experimental investigations of barrier height inhomogeneities in poly-Si/4H-SiC heterojunction diodes
Authors: Triendl F , Pfusterschmied G , Pobegen G , Konrath J P , Schmid U
Published: August 2020

p-Si/4H-SiC heterojunction diodes are realized by sputter-deposition of the Si top contact and subsequent post-deposition annealing at either 900 °C or 1000 °C. The high Schottky barrier height (SBH) of this junction architecture of around 1.65 V is ideal to analyze SBH inhomogeneities present in most Schottky- and heterojunctions. Current-voltage-temperature (IVT) and capacitance-voltage-temperature (CVT) measurements are conducted in a wide temperature range from 60 K up to 460 K while applying standard techniques for SBH extraction. Strong deviations from ideal IV characteristics are present especially at lowest temperatures when assuming a homogenous SBH. Additionally, the extracted SBHs at low temperatures differ a lot between the two methods, indicating the presence of low barrier conduction paths. The presence of at least two distinct SBH inhomogeneities is found, which are labeled as ‘intrinsic’ and ‘extrinsic’. Next, the Tung model was applied to fit the measured IVT data using a discretized Gaussian distribution of patch parameters to account for spreading resistance effects. By using multiple Gaussian distributions, excellent fitting results were achieved, giving the density values of the different patches and a background barrier height from the IVT data, which are in excellent agreement with the CVT data over a wide temperature range of 400 K.
Quench detection using Hall sensors in high-temperature superconducting CORC®-based cable-in-conduit-conductors for fusion applications
Authors: Weiss J D , Teyber R , Marchevsky M , van der Laan D C
Published: August 2020

Advanced magnet systems for fusion applications would greatly benefit from the use of high-temperature superconductors (HTS). These materials allow fusion magnets to operate at higher magnetic fields, allowing for more compact fusion machines, and allow for operation at elevated temperatures, enabling demountable coils that provide access for maintenance of the fusion reactor. Quench detection remains a major challenge in the protection of HTS magnets that are vulnerable to localized conductor burnout due to their low quench propagation velocities. One of the methods explored is the use of Hall sensors that are incorporated in or near the magnet terminations that can detect local field variations that occur as a result of current redistribution within the conductor to bypass a hotspot within the magnet winding. This method is potentially well suited for Cable in Conduit Conductors, such as those made from Conductor on Round Core (CORC) cables, in which sub-cables containing HTS tapes are connected to the terminations at a low resistance. To demonstrate the technique, a CORC® triplet consisting of three sub-cables, rated for 4 kA operation at 77 K, was manufactured and Hall sensors were used to measure local field variations next to the terminations due to current redistribution between the cables. The Hall response was compared to voltages that developed over the cables and terminations as a local hotspot was applied to different cables in the triplet. It was found that the Hall sensors were faster and more sensitive than voltage contact measurements and were able to reliably detect current redistribution of only a few amperes caused by a hotspot, well before the triplet exceeded its critical current. The method also allowed the detection of heater-induced hotspots during high ramp rates of 2 kA s−1 relevant for fusion applications. Hall sensors have a distinct benefit of being less sensitive to inductive pickup of AC interference compared to voltage contact measurements that make quench detection through voltage measurements in magnets especially challenging. The method can also be used for diagnostic measurements of current redistribution caused by other sources such as inhomogeneous current injection from faulty joints, or localized conductor damage. The Hall sensors are likely capable of detecting the onset of a quench that may occur a far distance away from the sensor location, presenting a breakthrough in HTS quench detection that potentially removes one of the remaining barriers to reliable operation of large HTS magnet systems.
Magnetic flux quantum in 2D correlated states of multiparticle charged system
Authors: Jacak Janusz E
Published: August 2020

We demonstrate that in a correlated 2D systems of electrons in the presence of perpendicular magnetic field the magnetic flux quantum may not achieve its value determined for a single or a noncorrelated electron. Correlations induced by the repulsion of electrons at strong magnetic field presence impose topological-type limits on planar cyclotron orbits which cause specific homotopy of trajectories resulting in constraints of the magnetic field flux quantum value. These restrictions occur at discrete series of magnetic field values corresponding to hierarchy of 2D correlated Hall states observed experimentally in GaAs thin films and in graphene. The similar homotopy property is observed in 2D Chern topological insulators when the magnetic field is substituted by the Berry field.
Electronic and optical properties of metal-doped TiO2 nanotubes: spintronic and photocatalytic applications
Authors: Fadlallah Mohamed M , Eckern Ulrich
Published: August 2020

Due to their characteristic geometry, TiO2 nanotubes (TNTs), suitably doped by metal-substitution to enhance their photocatalytic properties, have a high potential for applications such as clean fuel production. In this context, we present a detailed investigation of the magnetic, electronic, and optical properties of transition-metal doped TNTs, based on hybrid density functional theory. In particular, we focus on the 3d, the 4d, as well as selected 5d transition-metal doped TNTs. Thereby, we are able to explain the enhanced optical activity and photocatalytic sensitivity observed in various experiments. We find, for example, that Cr- and W-doped TNTs can be employed for applications like water splitting and carbon dioxide reduction, and for spintronic devices. The best candidate for water splitting is Fe-doped TNT, in agreement with experimental observations. In addition, our findings provide valuable hints for future experimental studies of the ferromagnetic/spintronic behavior of metal-doped titania nanotubes.
Quadrupole topological phase and robust corner resonance in Kekulé hexagonal electric circuit
Authors: Yao Junjie , Hao Xiamin , Luo Fangxue , Jia Yizhen , Zhou Miao
Published: August 2020

Two-dimensional (2D) quadrupole topological insulators, featured by topologically protected 0D corner modes, have recently attracted tremendous interest in condensed matter and materials physics. Herein, we construct a specific electric circuit made of capacitors and inductors forming a 2D Kekulé hexagonal lattice for quadrupole topological phase and corner modes. Trivial–nontrivial topological phase transition can be controlled by varying capacitance in the circuit, so that distinct topological edge states appear in 1D ribbons and corner states emerge in 0D flakes. We explore the field strength distribution and two-point impedance with respect to excitation frequency, and reveal that the topological corner resonance is robust against size of the LC network and randomness of the capacitors/inductors, a great benefit for experimental detection. Our results enrich the family of designer topoelectrical circuit as a flexible and tunable platform to achieve exotic quantum phases, which may have potential for future telecommunications, signal processing and quantum computing.
Decay properties of the Zc(3900) through the Fierz rearrangement *
Authors: Chen Hua-Xing
Published: August 2020

We systematically construct all the tetraquark currents/operators of JPC
 = 1+- with the quark configurations

,

, and

(

), and derive their relations through the Fierz rearrangement of the Dirac and color indices. Using the transformations of

and

, we study decay properties of the

as a compact tetraquark state; while using the transformation of

, we study its decay properties as a hadronic molecular state.
Revisiting nonfactorizable contributions to factorization-forbidden decays of B mesons to charmonium *
Authors: Li Ya-Qian , Jia Meng-Kun , Zhou Rui
Published: August 2020

Motivated by the large rates of

decays observed by the

and Belle collaborations, we investigate the nonfactorizable contributions to these factorization-forbidden decays, which can occur through a gluon exchange between the

system and the spectator quark. Our numerical results demonstrate that the spectator contributions are capable of producing a large branching ratio consistent with the experiments. As a by-product, we also study the Cabibbo-suppressed decays, such as

and the U-spin-related

decay, which have so far received less theoretical and experimental attention. The calculated branching ratios reach the order of

, which is within the scope of the Belle-II and LHCb experiments. Further, the

-asymmetry parameters are also calculated for these decays. The obtained results are compared with the available experimental data and numbers from other predictions. We also investigate the sources of theoretical uncertainties in our calculation.
Pion parton distribution function in light-front holographic QCD *
Authors: Chang Lei , Raya Khépani , Wang Xiaobin
Published: August 2020

The valence-quark distribution function of the pion has been of interest for decades; particularly, the profile it should adopt when

(the large-x behavior) has been the subject of a long-standing debate. In the light-front holographic QCD (LFHQCD) approach, this behavior is controlled by the so-called reparametrization function,

, which is not fully determined from first principles. We show that, owing to the flexibility of

, the large-x profile

can be contained within the LFHQCD formalism. This is in contrast to a previous LFHQCD study (Guy F. de Teramond et al., Phys. Rev. Lett., 120(18), 2018) in which

was found instead. Given our observations, augmented by perturbative QCD and recent lattice QCD results, we state that the large-x exponent of “2” cannot be excluded.
Near-threshold K*(892)+ meson production in the interaction of π− mesons with nuclei
Authors: Paryev E. Ya.
Published: August 2020

We study the inclusive production of strange vector

mesons in

reactions at near-threshold laboratory incident pion momenta of 1.4–2.0 GeV/c via a nuclear spectral function approach. The approach accounts for incoherent primary

meson–proton

production processes as well as the influence of the scalar

–nucleus potential (or the

in-medium mass shift) on these processes. We calculate the absolute differential and total cross sections for the production of

mesons from carbon and tungsten nuclei at laboratory angles of 0

–45

and at the aforementioned momenta in five scenarios for the aforenoted shift. We show that the

momentum distributions and their excitation functions (absolute and relative) possess a high sensitivity to changes in the in-medium

mass shift in the low-momentum region of 0.1–0.6 GeV/c. Therefore, the measurement of such observables in a dedicated experiment at the GSI pion beam facility in the near-threshold momentum domain will allow us to get valuable information on the

in-medium properties.
Facilitating stochastic resonance as a pre-emphasis method for neural spike detection
Authors: Güngör Cihan Berk , Töreyin Hakan
Published: August 2020

Objective. We aim to increase the number of neural spikes that can be detected in a single channel extracellular neural recording. Approach. We propose a pre-emphasis method facilitating stochastic resonance (SR), where we introduce the band-pass-filtered noisy extracellular recording to an overdamped Brownian particle in a monostable well. The x-position of the Brownian particle is the output of the proposed pre-emphasis method. Threshold is applied on the output for spike detection. To characterize the dynamics and the solution of the system, we use a synthetic dataset generated by adding Gaussian white noise at different intensities to an intracellular recording. Then, we evaluate and compare the spike detection performance of the proposed method on a public synthetic extracellular dataset. Main results. The proposed SR-based spike detection improves the signal-to-noise ratio of the intracellular-based synthetic dataset as much as 7.35 dB and outperforms the state-of-the-art pre-emphasis methods in false positive and false negative rates in 15 of the 16 synthetic extracellular datasets, with 100% sensitivity and positive predictivity values in seven of the recordings. Significance. The method has the potential of significantly increasing the number of neurons that can be monitored from a single-channel extracellular recording.