bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical modeling of ignition enhancement by repetitive nanosecond discharge in a hydrogen/air mixture II: forced ignition
Authors: Wang Yuan , Guo Peng , Chen Haitao , Chen Zheng 
Published: October 2020

Abstract
Non-equilibrium plasma has promising applications in combustion enhancement. In this study, 1D simulations are conducted for the forced ignition process using non-equilibrium plasma generated by repetitively pulsed nanosecond discharge (NSD). The ignition kernel is induced by a discharge area with NSD and it develops and propagates in a static stoichiometric hydrogen/air mixture. The objective is to assess how the characteristics of NSD affect the ignition delay time and ignition kernel development during the forced ignition process. Similar to the homogeneous ignition considered in part I, the forced ignition process is found to be strongly affected by the pulse number, discharge frequency, discharge radius, total input energy, and input energy per pulse of NSD. For a fixed input energy per pulse, the ignition delay time decreases and the propagation speed of the initial ignition kernel increases with the pulse number, discharge frequency and discharge radius. However, for a fixed total input energy, the ignition delay time increases and the propagation speed of the initial ignition kernel decreases with the pulse number. Furthermore, it is found that the promotion of ignition kernel development and propagation in the forced ignition by NSD are mainly due to the kinetic effect rather than the thermal effect.
Positronium formation at 4H SiC(0001) surfaces
Authors: Kawasuso A , Wada K , Miyashita A , Maekawa M , Iwamori H , Iida S , Nagashima Y 
Published: October 2020

Abstract
Positronium formation at 4H SiC(0001) surfaces were investigated upon the removal of natural oxide layers by hydrofluoric acid etching and heat treatment at 1000 K in ultra-high vacuum. Two types of positronium were observed in the positronium time-of-flight (PsTOF) measurements irrespective of conduction type and surface polarity. One type formed the major part of the PsTOF spectrum with a maximum energy of 4.7 ± 0.3 eV. This energy exceeded the theoretical value calculated with valence electrons. The PsTOF spectrum shape was different from those of metal surfaces, suggesting that the surface state electrons or conduction electrons need to be considered as the positronium source. Another positronium appeared at 1000 K in the tail of the PsTOF spectrum with a maximum energy of 0.2–0.5 eV. This thermally-assisted athermal positronium may be formed via the surface state positrons and electrons.
Metastable ferromagnetic flux closure-type domains in strain relaxed Gd0.1Ca0.9MnO3 thin films
Authors: Schulman A , Palonen H , Lähteenlahti V , Beiranvand A , Huhtinen H , Paturi P 
Published: October 2020

Abstract
We have systematically studied the structural, electrical transport, and magnetic properties of Gd0.1Ca0.9MnO3 thin films in function of thickness, which ranged from 22 nm up to 220 nm. We have found that, although no strong substrate-induced strain was detected for any thickness, a sudden change in the electric transport properties was observed when the film thickness increases above 80 nm. While thinner samples are insulating in the whole temperature range, the samples thicker than 80 nm show a clear insulator-to-metal transition (IMT) at around 100 K. The IMT coincides with the appearance of a ferromagnetic phase that is absent in the thinner samples. We associate this change in behavior with a critical film thickness that induces a sudden change in domain configuration, from in-plane domain to a closed flux-type domain with out-of-plane orientations. These out-of-plane oriented domains are meta-stable ferromagnetic in nature and result in an IMT which is accompanied by a hysteretic magnetoresistance behavior.
Imaginary-time time-dependent density functional theory for periodic systems
Authors: McFarland John , Manousakis Efstratios 
Published: October 2020

Abstract
Imaginary-time time-dependent density functional theory (it-TDDFT) has been proposed as an alternative method for obtaining the ground state within density functional theory (DFT) which avoids some of the difficulties with convergence encountered by the self-consistent-field (SCF) iterative method. It-TDDFT was previously applied to clusters of atoms where it was demonstrated to converge in select cases where SCF had difficulty with convergence. In the present work we implement it-TDDFT propagation for periodic systems by modifying the Quantum ESPRESSO (QE) package, which uses a plane-wave basis with multiple
k
points, and has the options of non-collinear and DFT + U calculations using ultra-soft or norm-conserving pseudo potentials. We demonstrate that our implementation of it-TDDFT propagation with multiple
k
points is correct for DFT + U non-collinear calculations and for DFT + U calculations with ultra-soft pseudo potentials. Our implementation of it-TDDFT propagation converges to the exact SCF energy (up to the decimal guaranteed by double precision) in all but one case where it converged to a slightly lower value than SCF, suggesting a useful alternative for systems where SCF has difficulty reaching the Kohn–Sham (KS) ground state. In addition, we demonstrate that more rapid convergence can be achieved if we use adaptive-size imaginary-time-steps for different kinetic-energy plane-waves.
Ionising radiation as a risk factor for lymphoma: a review
Authors: Harbron Richard W , Pasqual Elisa 
Published: October 2020

Abstract
The ability of ionising radiation to induce lymphoma is unclear. Here, we present a narrative review of epidemiological evidence of the risk of lymphoma, including chronic lymphocytic leukaemia (CLL) and multiple myeloma (MM), among various exposed populations including atomic bombing survivors, industrial and medical radiation workers, and individuals exposed for medical purposes. Overall, there is a suggestion of a positive dose-dependent association between radiation exposure and lymphoma. The magnitude of this association is highly imprecise, however, with wide confidence intervals frequently including zero risk. External comparisons tend to show similar incidence and mortality rates to the general population. Currently, there is insufficient information on the impact of age at exposure, high versus low linear energy transfer radiation, external versus internal or acute versus chronic exposures. Associations are stronger for males than females, and stronger for non-Hodgkin lymphoma and MM than for Hodgkin lymphoma, while the risk of radiation-induced CLL may be non-existent. This broad grouping of diverse diseases could potentially obscure stronger associations for certain subtypes, each with a different cell of origin. Additionally, the classification of malignancies as leukaemia or lymphoma may result in similar diseases being analysed separately, while distinct diseases are analysed in the same category. Uncertainty in cell of origin means the appropriate organ for dose response analysis is unclear. Further uncertainties arise from potential confounding or bias due to infectious causes and immunosuppression. The potential interaction between radiation and other risk factors is unknown. Combined, these uncertainties make lymphoma perhaps the most challenging malignancy to study in radiation epidemiology.
Exact lattice-model calculation of boundary modes for Weyl semimetals and graphene
Authors: Kaladzhyan Vardan , Pinon Sarah , Bardarson Jens H , Bena Cristina 
Published: October 2020

Abstract
We provide an exact analytical technique to obtain within a lattice model the wave functions of the edge states in zigzag- and bearded-edge graphene, as well as of the Fermi-arc surface states in Weyl semimetals described by a minimal bulk model. We model the corresponding boundaries as an infinite scalar potential localized on a line, and respectively within a plane. We use the T-matrix formalism to obtain the dispersion and the spatial distribution of the corresponding boundary modes. Furthermore, to demonstrate the power of our approach, we write down the surface Green’s function of the considered Weyl semimetal model, and we calculate the quasiparticle interference patterns originating from an impurity localized at the respective surface.
Strong large-scale climate response to North American sulphate aerosols in CESM
Authors: García-Martínez Ivonne M , Bollasina Massimo A , Undorf Sabine 
Published: October 2020

Abstract
The effects of increased North American sulphate aerosol emissions on the climate of Mexico and the United States (U.S.) during 1950–1975 are investigated by using two sets of transient coupled experiments with the Community Earth System Model, one with historically evolving emissions, and a second one where North American SO2 emissions are kept at their pre-industrial levels. The 1950–1975 increase in North American sulphate aerosols is found to have regional and remote impact. Over central U.S. and northern Mexico, the strengthening and westward expansion of the North Atlantic Subtropical High and subsequent intensification of the low-level easterlies, along with local aerosol interactions with radiation and clouds, cause a cooling trend and enhance precipitation. The interaction between the enhanced moisture transport across the Gulf of Mexico and the elevated topography of central Mexico favours positive rainfall on the Atlantic side while suppressing it on the Pacific side. These continental anomalies are embedded in a hemispheric-wide upper-tropospheric teleconnection pattern over the mid-latitudes, extending from the Pacific to the Atlantic basin. Details of the underlying mechanisms—in particular the prominent role of dynamical adjustments—are provided. With SO2 emissions considerably reduced in the U.S., and the expectation of a continued global decline throughout the 21st century, this study sheds light upon possible ongoing and future regional climate responses to changes in anthropogenic forcing.
From oxygen sensing to angiogenesis: Targeting the hypoxia signaling pathway in metastatic kidney cancer
Authors: Chung Clement 
Published: October 2020

AbstractPurposeThis article summarizes examples of current and emerging therapies that target the hypoxia and angiogenesis signaling pathways in the clear cell type of renal cell cancer (RCC), with an emphasis on the hypoxia signaling pathway.SummaryMammalian cells transduce signals of decreased oxygen to hypoxia inducible factor (HIF), an intracellular heterodimer that mediates the adaptation of normal and tumor cells to oxygen deprivation. HIF is frequently overexpressed in cancer cells and is involved in the transcriptional activation of many genes essential for cell invasion, migration, survival, and angiogenesis (including vascular endothelial growth factor [VEGF]). Moreover, HIF confers resistance to cytotoxic chemotherapy and radiation therapy and is associated with poor prognosis in patients with cancer. Blocking the activity of HIF inhibits the expression of VEGF and oncogenic pathways, resulting in the inhibition of tumor growth. Interestingly, activation of oncogenes and/or inactivation of tumor suppressor genes (eg, the gene encoding von Hippel-Lindau [VHL] tumor suppressor protein) can activate tumorigenesis even with normal levels of oxygen, providing support for the notion that the HIF-VHL-VEGF axis is amenable to targeted therapies for the treatment of RCC. This article highlights the current understanding of the hypoxia signaling pathway and its relevance to RCC development. Pharmacologic agents targeting the hypoxia and angiogenesis signaling pathways are discussed.ConclusionDevelopment of novel therapeutic agents that target the hypoxia and angiogenesis signaling pathways holds promise in the management of metastatic clear cell RCC.
Male–male contest limits the expression of assortative mate preferences in a polymorphic poison frog
Authors: Yang Yusan , Richards-Zawacki Corinne L 
Published: October 2020

Abstract
Codivergence of sexual traits and mate preferences can lead to assortative mating and subsequently reproductive isolation. However, mate choice rarely operates without intrasexual competition, and the effects of the latter on speciation are often overlooked. Maintaining trait polymorphisms despite gene flow and limiting assortative female preferences for less-competitive male phenotypes are two important roles that male–male competition may play in the speciation process. Both roles rely on the assumption that male–male competition limits the expression of divergent female preferences. We tested this assumption in the highly color-polymorphic strawberry poison frog (Oophaga pumilio). Females prefer males of the local color, suggesting that reproductive isolation may be evolving among color morphs. However, this inference does not account for male–male competition, which is also color-mediated. We housed females with two differently colored males, and compared reproductive patterns when the more attractive male was the territory holder versus when he was the nonterritorial male. Females mated primarily with the territory winner, regardless of coloration, suggesting that when a choice must be made between the two, male territoriality overrides female preferences for male coloration. Our results highlight the importance of considering the combined effects of mate choice and intrasexual competition in shaping phenotypic divergence and speciation.
Effects of Urethritis on Human Immunodeficiency Virus (HIV) in Semen: Implications for HIV Prevention and Cure
Authors: Chen Jane S , Matoga Mitch , Massa Cecilia , Tegha Gerald , Ndalama Beatrice , Bonongwe Naomi , Mathiya Esther , Jere Edward , Banda Gabriel , Loftis Amy J , Lancaster Kathryn E , Miller William C , Hoffman Irving F , Cohen Myron S 
Published: October 2020

Abstract

Background
Prior to the widespread availability of antiretroviral therapy (ART), men living with human immunodeficiency virus (HIV) with urethritis had increased concentrations of HIV in semen. This study aims to better evaluate HIV shedding in men with urethritis receiving ART, and its implications for the cure of HIV.

Methods
Men living with HIV with urethritis taking ART ≥12 weeks were enrolled at a sexually transmitted infections clinic in Lilongwe, Malawi. Study follow-up included visits at 1, 2, 4, 8, 12, 24, 36, and 48 weeks after urethritis diagnosis and treatment. Matched blood and semen samples were collected at all visits, and all additional episodes of urethritis were followed with extra visits 1, 2, and 4 weeks after treatment.

Results
There were 111 men enrolled in the study between January 2017–March 2019, and 77 (69%) were suppressed in the blood (&lt;400 copies/mL). Among the 77 men, 87 episodes of urethritis were evaluated during follow-up. Of the 87 episodes, 15 episodes (17%) had instances of seminal viral shedding ≥400 copies/mL despite viral suppression in the blood. During nonurethritis follow-up, ≤6% of men at each visit had a viral load ≥400 copies/mL in the semen while maintaining viral suppression in the blood.

Conclusions
An HIV cure requires the elimination of HIV from every body compartment, but available ART does not currently accomplish this. Our study highlights the male genital tract as a local source of HIV that can be reversibly activated. A better understanding of this phenomenon is important to advance the HIV cure field.
Compression with Wildcards: From CNFs to Orthogonal DNFs by Imposing the Clauses One-by-One
Authors: Wild Marcel 
Published: October 2020

Abstract
We present a novel technique for converting a Boolean conjunctive normal form (CNF) into an orthogonal disjunctive normal form (DNF), aka exclusive sum of products. Our method (which will be pitted against a hardwired command from Mathematica) zooms in on the models of the CNF by imposing its clauses one by one. Clausal imposition invites parallelization, and wildcards beyond the common don’t-care symbol compress the output. The method is most efficient for few but large clauses. Generalizing clauses, one can in fact impose superclauses. By definition, superclauses are obtained from clauses by substituting each positive literal by an arbitrary conjunction of positive literals.
Archives, Collections and Curatorship: Live Archive Projects in a Design History Learning Setting
Authors: Willcocks Judy 
Published: October 2020

Abstract
This article outlines a methodology for using uncatalogued archive material in a design history learning setting. The study references concepts such as experiential learning1 and object-based or object-centred learning,2 and draws on student reports and interviews to explore the potency of the learning experience. Using a specific case study addressing archives relating to Basic Design pedagogy at the Central School of Arts and Crafts it summarises the practicalities of enabling students to work with uncatalogued archive material and explores the pedagogic frameworks required to engage with curatorial practices in this context. Based on the case, the article recommends a flexible approach to archive material that has not yet been subject to formal archiving processes, viewing this as a time when a rich range of narratives can be uncovered through collaborative practice. It also references the history of design history and argues for more attention to be paid to the impact of design pedagogies on the creative and production processes. While the contents of the article are relevant to archival practice beyond the UK it is worth noting that the perspectives and stories considered in the article are UK-centred.
Jaguar (Panthera onca) density and tenure in a critical biological corridor
Authors: Foster R J , Harmsen B J , Urbina Y L , Wooldridge R L , Doncaster C P , Quigley H , Figueroa O A 
Published: October 2020

Abstract
We estimated jaguar density and tenure, and investigated ranging behavior, using camera traps across the Maya Forest Corridor, a human-influenced landscape in central Belize that forms the only remaining connection for jaguar populations inhabiting two regional forest blocks: the Selva Maya and the Maya Mountain Massif. Jaguars were ubiquitous across the study area. Similar to the neighboring Selva Maya, mean density ranged from 1.5 to 3.1 jaguars per 100 km2, estimated by spatial capture-recapture models. Cameras detected almost twice as many males as females, probably reflecting detection bias, and males ranged more widely than females within the camera grid. Both sexes crossed two major rivers, while highway crossings were rare and male-biased, raising concern that the highway could prevent female movement if traffic increases. Jaguars were more transient where the landscape was fragmented with settlements and agriculture than in contiguous forest. Compared with jaguars in the protected forests of the Maya Mountains, jaguars in central Belize displayed a lower potential for investment in intraspecific communication, indicative of a lower quality landscape; however, we did detect mating behavior and juveniles. Tenure of individuals was shorter than in the protected forests, with a higher turnover rate for males than females. At least three-quarters of reported jaguar deaths caused by people were male jaguars, and the majority was retaliation for livestock predation. Jaguars seem relatively tolerant to the human-influenced landscape of central Belize. However, intensification of game hunting and lethal control of predators would threaten population persistence, while increased highway traffic and clear-cutting riparian forest would severely limit the corridor function. Our results show that the viability of the corridor, and thus the long-term survival of jaguar populations in this region, will depend on appropriate land-use planning, nonlethal control of livestock predators, enforcement of game hunting regulations, and wildlife-friendly features in future road developments.
Is There a Minimum Number of Landmarks That Optimizes the Geometric Morphometric Analysis of Mosquito (Diptera, Culicidae) Wings?
Authors: Beriotto Agustina C , Garzón Maximiliano J , Schweigmann Nicolás 
Published: October 2020

Abstract
Culicids are the most significant arthropods affecting human health. Thus, their correct identification is critical. The use of Geometric Morphometrics (GM) has been recently incorporated into mosquito taxonomy and has begun to complement classic diagnostic techniques. Since sampling size depends on the number of Landmarks (LMs) used, this study aimed to establish the minimum number of wing LMs needed to optimize GM analysis of mosquito species and/or genera from urban and peri-urban areas of Argentina. Female left wings were used for the optimization phase, in which 17 LMs were reduced to four by iterative LM exclusion. To verify its efficiency, Principal Component Analysis (PCA), Discriminant Analysis (DA), and Canonical Variate Analysis (CVA) were performed. Additionally, a phenogram was constructed to visualize the results. We observed that five LMs for the PCA, CVA, and phenogram and nine for the DA enabled discrimination and/or clustering of almost all species and genera. Therefore, we tested the LM selection by using nine LMs and adding new species. The resulting PCA showed little overlap between species and almost all species clustered as expected, which was also reflected in the phenogram. Significant differences were found between wing shape among all species, together with a low total error rate in the DA. In conclusion, the number of LMs can be reduced and still be used to effectively differentiate and cluster culicids. This is helpful for better exploitation of available material and optimization of data processing time when classic taxonomy methods are inadequate or the material is scarce.
Intra-fractional patient setup error during fractionated intracranial stereotactic irradiation treatment of patients wearing medical masks: comparison with and without bite block during COVID-19 pandemic
Authors: Ohira Shingo , Kanayama Naoyuki , Komiyama Riho , Ikawa Toshiki , Toratani Masayasu , Ueda Yoshihiro , Washio Hayate , Miyazaki Masayoshi , Koizumi Masahiko , Teshima Teruki 
Published: October 2020

Abstract
The immobilization of patients with a bite block (BB) carries the risk of interpersonal infection, particularly in the context of pandemics such as COVID-19. Here, we compared the intra-fractional patient setup error (intra-SE) with and without a BB during fractionated intracranial stereotactic irradiation (STI). Fifteen patients with brain metastases were immobilized using a BB without a medical mask, while 15 patients were immobilized without using a BB and with a medical mask. The intra-SEs in six directions (anterior–posterior (AP), superior–inferior (SI), left–right (LR), pitch, roll, and yaw) were calculated by using cone-beam computed tomography images acquired before and after the treatments. We analyzed a total of 53 and 67 treatment sessions for the with- and without-BB groups, respectively. A comparable absolute mean translational and rotational intra-SE was observed (P &gt; 0.05) in the AP (0.19 vs 0.23 mm with- and without-BB, respectively), SI (0.30 vs 0.29 mm), LR (0.20 vs 0.29 mm), pitch (0.18 vs 0.27°), roll (0.23 vs 0.23°) and yaw (0.27 vs 22°) directions. The resultant planning target volume (PTV) margin to compensate for intra-SE was &lt;1 mm. No statistically significant correlation was observed between the intra-SE and treatment times. A PTV margin of &lt;1 mm was achieved even when patients were immobilized without a BB during STI dose delivery.