bluuebunny/crossref_metadata_2025_split huggingface dataset:
Formation and propagation of ionization waves during ns pulse breakdown in plane-to-plane geometry
Authors: Orr Keegan , Yang Xin , Gulko Ilya , Adamovich Igor V 
Published: July 2020

Abstract
Ionization wave development during ns pulse breakdown in nitrogen between two parallel plate, dielectric-covered electrodes is studied by ps electric field induced second harmonic (EFISH) generation and kinetic modeling. The results indicate formation of two well-defined ionization waves in the discharge gap, which requires a relatively high initial electron density. The first, anode-directed, wave is produced by ‘sweeping’ the initial electrons by the applied voltage pulse. The second wave originates between the cathode and the first wave front, due to the field enhancement in this region, generating two wave fronts propagating in opposite directions and observed in plasma emission images. Only the anode-directed front of the second wave is detected by the EFISH measurements, most likely due to the proximity of the cathode-directed front to the wall. Both the measurements and the modeling predictions exhibit a transient electric field overshoot in the center of the gap, caused by the anode-directed front of the second wave. The boundary between the plasma domains formed ahead of the first wave and behind the second wave, observed in the plasma emission images, is detected by the EFISH measurements and predicted by the modeling calculations. The electron density and coupled energy distributions predicted by the model at the end of the discharge pulse are nearly uniform, except near the cathode-adjacent wall, where the applicability of the present model is uncertain and which is not accessible to the EFISH measurements.
Development of multi-layered electromagnetic system for improving base isolator using a magnetorheological elastomer
Authors: Hwang Yongmoon , Lee Junghoon , Kye Seungkyung , Jung Hyung-Jo 
Published: July 2020

Abstract
Magnetorheological elastomer (MRE) is one of the smart materials whose stiffness and damping ratios can be controlled by applying a magnetic field. Several studies have been conducted on the utilization of MREs as base isolators in semi-active systems. A base isolator using a MRE utilizes an electromagnetic system to generate a magnetic field for the MRE. Generally, single-layered electromagnetic systems are used in MRE-based isolators. The single-layered electromagnetic system forms an inter-space between the MRE and the electromagnetic system to consider the deformation of the MRE. A larger inter-space is observed when the strain of the MRE is increased, which causes limitations owing to the excessive volume and electric power of the base isolator. Therefore, a electromagnetic system is proposed to overcome these limitations, in which the single-layered electromagnetic system is divided into several layers and behaves according to the deformation of the MRE. To validate the superiority of the proposed electromagnetic system, numerical analyses were conducted, using ANSYS Electronics, to compare its magnetic flux density, resistance, size, and volume. Based on the results of these analyses, dynamic characteristic tests were performed to compare the MR effects in each system.
Shape memory alloy actuator with active cooling device and deflectable winglet application
Authors: Mao Zhiwen , Xu Zhiwei , Wang Qi 
Published: July 2020

Abstract
Heating and cooling time directly influence the response speed of a shape memory alloy (SMA) wire actuator. An SMA wire is heated quickly by electric current, however quickly cooling it to a given temperature is difficult. In this study, we proposed a pipeline-type active air convection cooling scheme, which uses compressed air as cooling airflow to achieve rapid active cooling of SMA wire actuators. We designed an SMA wire linear actuator consisting of SMA wires, a compressed air tank, an air valve, an Outlet Pipeline, an SMA Cooling Pipeline, and some other additional accessories. We established theoretical models of heat transfer under natural cooling and active convection cooling of an SMA wire. In addition, we carried out theoretical simulation and experiments on a NiTi alloy SMA wire with a diameter of 1 mm and compared the accuracy of simulation with test results. The SMA wire actuators are used for deflectable morphing winglets of aircraft wing. We designed three-dimensional numerical models of the morphing winglets that can be deflected within ±20° and the experimental models are machined and assembled. Final test results show that active cooling time is reduced by more than 70% compared with natural cooling and the response speed is improved significantly.
Interleaved intramuscular stimulation with minimally overlapping electrodes evokes smooth and fatigue resistant forces
Authors: Eladly Ahmed , Del Valle Jaume , Minguillon Jesus , Mercadal Borja , Becerra-Fajardo Laura , Navarro Xavier , Ivorra Antoni 
Published: July 2020

Abstract

Objective. It is known that multi-site interleaved stimulation generates less muscle fatigue compared to single-site synchronous stimulation. However, in the limited number of studies in which intramuscular electrodes were used, the fatigue reduction associated with interleaved stimulation could not consistently be achieved. We hypothesize that this could be due to the inability to place the intramuscular electrodes used in interleaved stimulation in locations that minimize overlap amongst the motor units activated by the electrodes. Our objective in the present study was to use independent intramuscular electrodes to compare fatigue induced by interleaved stimulation with that generated by synchronous stimulation at the same initial force and ripple. Approach. In the medial gastrocnemius muscle of an anesthetized rabbit (n = 3), ten intramuscular hook wire electrodes were inserted at different distances from the nerve entry. Overlap was measured using the refractory technique and only three electrodes were found to be highly independent. After ensuring that forces obtained by both stimulation modalities had the same ripple and magnitude, fatigue induced during interleaved stimulation across three independent distal electrodes was compared to that obtained by synchronously delivering pulses to a single proximal electrode. Main results. Contractions evoked by interleaved stimulation exhibited less fatigue than those evoked by synchronous stimulation. Twitch force recruitment curves collected from each of the ten intramuscular electrodes showed frequent intermediate plateaus and the force value at these plateaus decreased as the distance between the electrode and nerve entry increased. Significance. The results indicate that interleaved intramuscular stimulation is preferred over synchronous intramuscular stimulation when fatigue-resistant and smooth forces are desired. In addition, the results suggest that the large muscle compartments innervated by the primary intramuscular nerve branches give rise to progressively smaller independent compartments in subsequent nerve divisions.
Experimental validation of inventory simulations on molybdenum and its isotopes for fusion applications
Authors: Gilbert M.R. , Packer L.W. , Stainer T. 
Published: July 2020

Abstract
Molybdenum is a potential material for future nuclear fusion experiments and power plants. It has good thermo-mechanical properties and can be readily fabricated, making it attractive as an alternative material to tungsten (the current leading candidate) for high neutron flux and high thermal load regions of fusion devices. Unfortunately, exposure to fusion neutrons is predicted to cause significant radioactivity in elemental Mo for decades and centuries after exposure, which would be a problem during maintenance and decommissioning operations. Simulation predictions indicate that Mo activation could be reduced by isotopic adjustment (biasing). If these predictions are proven and validated, and if isotopic adjustment is technically and economically feasible, then Mo could be used in future demonstration and commercial reactors without significantly increasing the amount of long-term, higher-level radioactive waste.
Transmutation (inventory) simulations used to predict activation rely on nuclear reaction data. The quality of these data impact on the confidence and uncertainty associated with predictions. Recently, UKAEA has developed benchmarks to test and validate the FISPACT-II inventory code and the input nuclear data libraries. Verification of molybdenum inventory simulations is performed against experimental decay-heat measurements from JAEA’s fusion neutron source (FNS) facility and using new data acquired from γ-spectroscopy measurements of Mo irradiated in the ASP 14 MeV facility in the UK.
Results demonstrate that FISPACT-II predictions (with TENDL-2019 nuclear data) for Mo are accurate on the short-timescales (minutes, hours of irradiation and minutes, days, weeks of cooling) of these laboratory experiments. However, these kinds of experiments are limited in their coverage of the important radionuclides for decay radiation from Mo on the years, decades and beyond timescales. Further experiments with fusion relevant conditions and timescales, potentially with alternative measurement techniques, are still needed.
Periodic quantum graphs with predefined spectral gaps
Authors: Khrabustovskyi Andrii 
Published: July 2020

Abstract
Let Γ be an arbitrary

Z

n

-periodic metric graph, which does not coincide with a line. We consider the Hamiltonian

H

ε

on Γ with the action −ɛ
−1d2/dx
2 on its edges; here ɛ > 0 is a small parameter. Let

m
∈
N

. We show that under a proper choice of vertex conditions the spectrum

σ

(

H

ε

)

of

H

ε

has at least m gaps as ɛ is small enough. We demonstrate that the asymptotic behavior of these gaps and the asymptotic behavior of the bottom of

σ

(

H

ε

)

as ɛ → 0 can be completely controlled through a suitable choice of coupling constants standing in those vertex conditions. We also show how to ensure for fixed (small enough) ɛ the precise coincidence of the left endpoints of the first m spectral gaps with predefined numbers.
Silicon waveguides with graphene: coupling of waveguide mode to surface plasmons
Authors: Čtyroký Jiří , Petráček Jiří , Kuzmiak Vladimír , Kwiecien Pavel , Richter Ivan 
Published: July 2020

Abstract
Silicon waveguides with graphene layers have been recently intensively studied for their potential as fast and low-power electro-optic modulators with small footprints. In this paper we show that in the optical wavelength range of 1.55 μm, surface plasmons supported by the graphene layer with the chemical potential exceeding ∼0.5 eV can couple with the guided mode of the silicon waveguide and affect its propagation. On the other hand, this effect might be possibly utilized in technical applications like a very low-power amplitude modulation, temperature sensing, etc.
Confocal laser scanning microscopy as a real-time quality-assessment tool for industrial graphene synthesis
Authors: Kim Dong Jin , Lee Chang-Won , Suh Yeonjoon , Jeong Heejeong , Jo Insu , Moon Joonhee , Park Mina , Woo Yun Sung , Hong Byung Hee 
Published: July 2020

Abstract
For the industrial quality control (QC) of the chemical vapor deposition (CVD) graphene, it is essential to develop a method to screen out unsatisfactory graphene films as efficiently as possible. However, previously proposed methods based on Raman spectroscopy or optical imaging after chemical etching are unable to provide non-invasive and fast analysis of large-area graphene films as grown on Cu foil substrates. Here we report that the reflection mode of confocal laser scanning microscopy (CLSM) provides a high-contrast image of graphene on Cu, enabling the real-time evaluation of the coverage and quality of graphene. The reflectance contrast, Rc, was found to be dependent on the incident laser wavelength, of which the maximum was obtained at 405 nm. In addition, Rc decreases with increasing defect density of graphene. The dependence of Rc on the graphene’s quality and laser wavelengths were explained by the tight-binding model calculation based on the Fresnel’s interference formula. Thus, we believe that the reflection mode CLSM would be a very powerful quality-assessment tool for the mass production of CVD graphene films grown on Cu.
Impact of mating system on range size and niche breadth inEpipactis(Orchidaceae)
Authors: Evans Alexandra , Jacquemyn Hans 
Published: July 2020

AbstractBackground and AimsThe geographical distribution of plant species is linked fundamentally not only to environmental variables, but also to key traits that affect the dispersal, establishment and evolutionary potential of a species. One of the key plant traits that can be expected to affect standing genetic variation, speed of adaptation and the capacity to colonize and establish in new habitats, and therefore niche breadth and range size, is the plant mating system. However, the precise role of the mating system in shaping range size and niche breadth of plant species remains unclear, and different studies have provided contrasting results. In this study, we tested the hypothesis that range size and niche breadth differed with mating system in the orchid genus Epipactis.MethodsWe modelled the ecological niches of 14 Epipactis species in Europe using occurrence records and environmental satellite data in Maxent. Niche breadth and niche overlap in both geographic and environmental space were calculated from the resulting habitat suitability maps using ENMTools, and geographic range was estimated using α-hull range definition. Habitat suitability, environmental variable contributions and niche metrics were compared among species with different mating systems.Key ResultsWe did not detect significant differences in niche breadth, occurrence probability or geographical range between autogamous and allogamous Epipactis species, although autogamous species demonstrated notably low variation in niche parameters. We also found no significant differences in niche overlap between species with the same mating system or different mating systems. For all Epipactis species, occurrence was strongly associated with land cover, particularly broad-leafed and coniferous forests, and with limestone bedrock.ConclusionsThese results suggest that the mating system does not necessarily contribute to niche breadth and differentiation, and that other factors (e.g. mycorrhizal specificity) may be more important drivers of range size and niche breadth in Epipactis and orchids in general.
Recent hybrid speciation at the origin of the narrow endemicPulmonaria helvetica
Authors: Grünig Sandra , Fischer Markus , Parisod Christian 
Published: July 2020

AbstractBackground and AimsHybridization is known to drive plant speciation through the establishment of homoploid or allopolyploid hybrid species. Here we investigate the origin of Pulmonaria helvetica, a narrow endemic species described across a restricted area of Switzerland that was entirely covered by ice during the last glacial maximum. This species presents an original number of chromosomes (2n = 24) and morphological traits suggestive of a hybrid origin.MethodsWe sequenced a plastid locus and 1077 double-digest restriction-site-associated DNA (ddRAD) loci in 67 individuals from across the distribution range of P. helvetica and candidate progenitor species growing in the same area. Assignment of genotypes to main genetic clusters within and among taxa using STRUCTURE tested whether P. helvetica represents a genetically differentiated lineage and addressed the hypothesis of its hybrid origin. Comparative ecological modelling further addressed possible niche differentiation among taxa.Key ResultsPulmonaria helvetica was highlighted as a genetically homogeneous species distinct from co-occurring taxa. Consistent with a scenario of hybrid speciation, it presented clear evidence of balanced admixture between Pulmonaria officinalis (2n = 16) and Pulmonaria mollis s.l. (2n = 18, 22), which was also highlighted as a maternal progenitor based on plastid sequences. Limited genetic structure within the maternal progenitor is consistent with an origin of P. helvetica through either homoploid hybridization with considerable karyotype changes or via complex scenarios of allopolyploidy involving a dysploid taxon of P. mollis s.l. Comparative niche modelling indicated non-significant ecological differences between P. helvetica and its progenitors, supporting intrinsic factors resulting from hybridization as main drivers of speciation.ConclusionsHybridization appears as a major process having promoted the postglacial origin of the narrow endemic P. helvetica, suggesting hybrid speciation as an effective process that rapidly produces new species under climate changes.
Nut and peanut butter intake and the risk of colorectal cancer and its anatomical and molecular subtypes: the Netherlands Cohort Study
Authors: Nieuwenhuis Lisette , Simons Colinda C J M , Weijenberg Matty P , van den Brandt Piet A 
Published: July 2020

AbstractNut intake has been associated with reduced total cancer-related mortality, but evidence for colorectal cancer (CRC) risk is inconclusive. We investigated the associations between nut and peanut butter intake and anatomical CRC subtypes. To account for molecular heterogeneity, associations between nut and peanut butter intake and colorectal tumors harboring APC, KRAS or BRAF mutations, p53 overexpression or microsatellite instability were examined in secondary analyses. In the Netherlands Cohort Study (n = 120 852), lifestyle habits were measured with a questionnaire in 1986. After 20.3 years follow-up, 3567 CRC cases were included in case–cohort analyses. For the analyses of molecular CRC subtypes, 574 cases were included after 7.3 years follow-up. In categorical analyses, total nut intake was not significantly associated with CRC [HR (95% CI) 10+ g/day versus non-consumers = 0.94(0.78–1.15) in men; 0.96(0.75–1.22) in women]. In restricted cubic spline analyses, significant non-linear inverse associations with rectal cancer were observed for total nut, peanut and peanut butter intake in women, and borderline significant non-linear inverse associations for total nut and peanut intake in men. Regarding the molecular CRC subtypes, peanut butter intake was significantly associated with an increased risk of colorectal tumors that did not develop through the serrated neoplasia pathway in men [HR (95% CI) per 5 g/day increment = 1.22(1.07–1.38)]. Nut and peanut butter intake are non-linearly inversely associated with rectal cancer risk in women. In men, nut intake is borderline significantly non-linearly associated with a reduced rectal cancer risk. Peanut butter is associated with an increased risk of colorectal tumors that do not develop through the serrated neoplasia pathway in men.
The Long Shadow of Youth: Girls’ Transition From Full-Time Education and Later-Life Subjective Well-Being in the English Longitudinal Study of Ageing
Authors: Xue Baowen , Tinkler Penny , McMunn Anne 
Published: July 2020

Abstract

Objectives
To investigate whether the timing and nature of women’s transitions out of full-time (FT) education are related to later-life subjective well-being and the life-course experiences that might explain any associations seen.

Methods
Data are from women in Wave 3 of the English Longitudinal Study of Ageing who have participated in the life history interview and were aged 50+ at the interview (n = 3,889). Using multichannel sequence analysis, we identified 6 types of transition out of FT education (ages 14–26). Regression models were used to examine associations between transition types and life satisfaction, quality of life, and depressive symptoms at age 50+.

Results
Women who made early transitions to married parenthood and FT domestic labor had lower levels of well-being on all 3 later-life well-being outcomes (p &lt; .01), compared to women who made later transitions to family life and remained employed. Women who remained single up to age 26 also had lower life satisfaction (p &lt; .05) and quality of life (p &lt; .01) in later life than their counterparts who married and had children. These associations were explained by the life-course socioeconomic and relationship pathways. Advantaged childhood socioeconomic circumstances and higher educational qualifications set “Later Marriage and Later employment” women apart onto advantaged trajectories and a better quality of life later (p &lt; .01).

Discussion
The timing and nature of exits from FT education played a pivotal role in setting people onto life-course trajectories that influence well-being in later life for this older generation of women.
Emerging roles of phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate as regulators of multiple steps in autophagy
Authors: Baba Takashi , Balla Tamas 
Published: July 2020

Abstract
Inositol phospholipids are low-abundance regulatory lipids that orchestrate diverse cellular functions in eukaryotic organisms. Recent studies have uncovered involvement of the lipids in multiple steps in autophagy. The late endosome–lysosome compartment plays critical roles in cellular nutrient sensing and in the control of both the initiation of autophagy and the late stage of eventual degradation of cytosolic materials destined for elimination. It is particularly notable that inositol lipids are involved in almost all steps of the autophagic process. In this review, we summarize how inositol lipids regulate and contribute to autophagy through the endomembrane compartments, primarily focusing on PI4P and PI(4,5)P2.
The dynamics of the nuclear environment and their impact on gene function
Authors: Zannino Lorena , Casali Claudio , Siciliani Stella , Biggiogera Marco 
Published: July 2020

Abstract
In the last decades, it has become increasingly clear how the modulation of spatial organization of chromatin over time and through the cell cycle is closely connected to gene function regulation. Different physicochemical stimuli contribute to the realization of specific transcriptional programs and finally to a specific cellular phenotype. In this review, we aim to describe the current knowledge about the dynamics regulating the movements and the interactions of molecules within the nucleus and their impact on gene functions. In particular, taking into account that these forces exert their effect in a nuclear environment characterized by a high concentration of molecules, we will discuss the role of proteins and structures that regulate these movements and transduce physicochemical signals acting on the cell to the nucleus.
Affirming Radical Equality in the Context of COVID-19: Human Rights of Older People and People with Disabilities
Authors: Akerkar Supriya 
Published: July 2020

Abstract
This paper discusses the impact of COVID-19 on older people and people with disabilities. It draws attention to the violations of their human rights in the context of COVID-19 which in turn reveal the hierarchical social order of our society. Although statistics show higher deaths of older people in regard to COVID-19, these numbers co-exist with rampant discrimination towards these groups with underlying messaging that their lives are dispensable. The paper highlights violations at different levels—discursive, ethical, and everyday—and shows how they are underpinned by ageism and disablism which stereotype older people and people with disabilities with prejudicial messaging and actions by states and societal actors. At the same time, the paper also highlights the value of human rights discourses and instruments which are mobilized by the disability movement and groups upholding the rights of older people, to question these rights infringements in the context of COVID-19. The politics of these groups which call for principled equality and inclusion of older people and people with disabilities in times of COVID-19 exhibit a much-needed disruption of our social order, an undertaking that needs to be continued in COVID-19 times and after.