Reversal Of Asymmetry Research Articles

Asymmetry of the Frontal Aslant Tract and Development of Supplementary Motor Area Syndrome

Background/Objectives: The purpose of this study was to investigate preoperative interhemispheric differences of the FAT in relation to the onset of postoperative SMA syndrome. Methods: This was a single-center retrospective analysis of patients who underwent surgical resection of diffuse gliomas involving the SMA between 2018 and 2022. Inclusion criteria were availability of preoperative and postoperative Magnetic Resonance Imaging, no previous surgery, and no neurological deficits at presentation. Diffusion-weighted data were processed by spherical deconvolution (SD) and diffusion tensor imaging tractography algorithms, and TrackVis was used to dissect the FAT of both hemispheres. The FAT data were analyzed for correlation with postoperative SMA syndrome onset. Results: N = 25 cases were included in the study, among which n = 23 had preoperative bilaterally identifiable FAT by SD. N = 12 developed an SMA syndrome, 6 demonstrated a motor-only syndrome, 4 had a verbal-only syndrome, and 2 had mixed verbal and motor features. The SMA syndrome incidence was significantly more frequent in lower-grade gliomas (p = 0.005). On the tumor side, the FAT identified by SD was smaller than the contralateral (mean volume 6.53 cm3 and 13.33 cm3, respectively, p < 0.001). In the 6 cases that developed a verbal SMA syndrome, a normalized FAT volume asymmetry (FAT-VA) demonstrated an asymmetry shifted towards the non-dominant side (mean FAT-VA = −0.68), while the cases with no postoperative verbal impairment had opposite asymmetry towards the dominant side (mean FAT-VA = 0.42, p = 0.010). Conclusions: Preoperative interhemispheric FAT volume asymmetry estimated according to functional dominance can predict postoperative onset of verbal SMA syndrome, with proportionally smaller FAT on the affected dominant hemisphere.

Natural reversal of cavefish heart asymmetry is controlled by Sonic Hedgehog effects on the left-right organizer.

The direction of left-right visceral asymmetry is conserved in vertebrates. Deviations of the standard asymmetric pattern are rare, and the underlying mechanisms are not understood. Here, we use the teleost Astyanax mexicanus, consisting of surface fish with normal left-oriented heart asymmetry and cavefish with high levels of reversed right-oriented heart asymmetry, to explore natural changes in asymmetry determination. We show that Sonic Hedgehog (Shh) signaling is increased at the posterior midline, Kupffer's vesicle (the teleost left-right organizer) is enlarged and contains longer cilia, and the number of dorsal forerunner cells is increased in cavefish. Furthermore, Shh increase in surface fish embryos induces asymmetric changes resembling the cavefish phenotype. Asymmetric expression of the Nodal antagonist Dand5 is equalized or reversed in cavefish, and Shh increase in surface fish mimics changes in cavefish dand5 asymmetry. Shh decrease reduces the level of right-oriented heart asymmetry in cavefish. Thus, naturally occurring modifications in cavefish heart asymmetry are controlled by the effects of Shh signaling on left-right organizer function.

Purifying selection drove the adaptation of mitochondrial genes along with correlation of gene rearrangements and evolutionary rates in two subfamilies of Whitefly (Insecta: Hemiptera).

Insectmitochondrial genomes(mitogenomes) are usually represented by a conserved gene order. Whiteflies exhibit gene rearrangement in their mitogenomes; however, understanding how nucleotide substitution rates shape gene rearrangement in whiteflies is unclear due to the limited number of mitogenomes. Additionally, the mechanisms by which selection pressure drives adaptations in mitochondrial genes in the two subfamilies of whiteflies are not yet known. Here, we analyzed 18 whitefly mitogenomes, including one newly generated mitogenome, to compare nucleotide substitution rates, selection pressure, and gene arrangements. The newly generated mitogenome is reported along with reannotation of Pealius mori and comparisons to other whitefly mitogenomes. Comparative studies on nucleotide composition of 18 whiteflies revealed the positive GC skewness, confirming the reversal of strand asymmetry. We found 11 rearranged gene orders within two subfamilies of whiteflies with 8-18 breakpoints of gene rearrangements. Members of the subfamily Aleyrodinae exhibit more complex pathways in the evolution of gene order as compared to the subfamily Aleurodicinae. Our findings also revealed that the increase or reduction of nucleotide substitution rates does not have an impact on any of the gene rearrangement scenarios depicting neutral correlation. Selection pressure analysis revealed that the mitogenomes from members of both the subfamilies Aleurodicinaeand Aleyrodinae are characterized by intense purifying selection pressure.

Sample Size Determination and Study Design Impact on Dose-Scale Pharmacodynamic Bioequivalence: a Case Study Using Orlistat.

Dose-scale pharmacodynamic bioequivalence is recommended for evaluating the consistency of generic and innovator formulations of certain locally acting drugs, such as orlistat. This study aimed to investigate the standard methodology for sample size determination and the impact of study design on dose-scale pharmacodynamic bioequivalence using orlistat as the model drug. A population pharmacodynamic model of orlistat was developed using NONMEM 7.5.1 and utilized for subsequent simulations. Three different study designs were evaluated across various predefined relative bioavailability ratios of test/reference (T/R) formulations. These designs included Study Design 1 (2×1 crossover with T1 60 mg, R1 60 mg, and R2 120 mg), Study Design 2 (2×1 crossover with T2 120 mg, R1 60 mg, and R2 120 mg), and Study Design 3 (2×2 crossover with T1 60 mg, T2 120 mg, R1 60 mg, and R2 120 mg). Sample sizes were determined using a stochastic simulation and estimation approach. Under the same T/R ratio and power, Study Design 3 required the minimum sample size for bioequivalence, followed by Study Design 1, while Study Design 2 performed the worst. For Study Designs 1 and 3, a larger sample size was needed on the T/R ratio < 1.0 side for the same power compared to that on the T/R ratio > 1.0 side. The opposite asymmetry was observed for Study Design 2. We demonstrated that Study Design 3 is most effective for reducing the sample size for orlistat bioequivalence studies, and the impact of T/R ratio on sample size shows asymmetry.

Brain (Yakovlevian) torque direction is associated with volume asymmetry of the intracranial transverse sinuses: evidence from situs inversus totalis.

Previous research reported reversal of the prototypical brain torque in individuals with mirrored visceral topology (situs inversus totalis, SIT). Here, we investigate if typical asymmetry of the posterior intracranial venous system is also reversed in SIT and whether the direction and magnitude of this asymmetry is related to the direction and magnitude of the brain torque. Brain structural MRI images of 38 participants with SIT were compared with those of 38 matched control participants. Occipital and frontal petalia and bending were measured using a standardized procedure. In addition, representative sections of the left and right transverse sinuses were segmented, and their respective volumes determined. Participants with SIT showed general reversal of occipital and frontal petalia and occipital bending, as well as reversal of typical transverse sinus asymmetry. Transverse sinus volume was significantly correlated with several torque measures, such that the smaller transverse sinus was associated with a larger ipsilateral occipital petalia, contralateral occipital bending, and ipsilateral frontal bending. We propose an anatomical mechanism to explain occipital petalia and bending, and conclude that anatomical constraints imposed by the asymmetry of the posterior venous system provide and additional account to elucidate the formation of the human brain torque.

Comparative mitogenomic analysis provides evolutionary insights into Formica (Hymenoptera: Formicidae).

Formica is a large genus in the family Formicidae with high diversity in its distribution, morphology, and physiology. To better understand evolutionary characteristics of Formica, the complete mitochondrial genomes (mitogenomes) of two Formica species were determined and a comparative mitogenomic analysis for this genus was performed. The two newly sequenced Formica mitogenomes each included 37 typical mitochondrial genes and a large non-coding region (putative control region), as observed in other Formica mitogenomes. Base composition, gene order, codon usage, and tRNA secondary structure were well conserved among Formica species, whereas diversity in sequence size and structural characteristics was observed in control regions. We also observed several conserved motifs in the intergenic spacer regions. These conserved genomic features may be related to mitochondrial function and their highly conserved physiological constraints, while the diversity of the control regions may be associated with adaptive evolution among heterogenous habitats. A negative AT-skew value on the majority chain was presented in each of Formica mitogenomes, indicating a reversal of strand asymmetry in base composition. Strong codon usage bias was observed in Formica mitogenomes, which was predominantly determined by nucleotide composition. All 13 mitochondrial protein-coding genes of Formica species exhibited molecular signatures of purifying selection, as indicated by the ratio of non-synonymous substitutions to synonymous substitutions being less than 1 for each protein-coding gene. Phylogenetic analyses based on mitogenomic data obtained fairly consistent phylogenetic relationships, except for two Formica species that had unstable phylogenetic positions, indicating mitogenomic data are useful for constructing phylogenies of ants. Beyond characterizing two additional Formica mitogenomes, this study also provided some key evolutionary insights into Formica.

Strategic Structural Control of Polyserotonin Nanoparticles and Their Application as pH-Responsive Nanomotors.

Serotonin-based nanomaterials have been positioned as promising contenders for constructing multifunctional biomedical nanoplatforms due to notable biocompatibility, advantageous charge properties, and chemical adaptability. The elaborately designed structure and morphology are significant for their applications as functional carriers. In this study, we fabricated anisotropic bowl-like mesoporous polyserotonin (PST) nanoparticles with a diameter of approximately 170 nm through nano-emulsion polymerization, employing P123/F127 as a dual-soft template and 1,3,5-trimethylbenzene (TMB) as both pore expander and emulsion template. Their formation can be attributed to the synchronized assembly of P123/F127/TMB, along with the concurrent manifestation of anisotropic nucleation and growth on the TMB emulsion droplet surface. Meanwhile, the morphology of PST nanoparticles can be regulated from sphere- to bowl-like, with a particle size distribution ranging from 432 nm to 100 nm, experiencing a transformation from a dendritic, cylindrical open mesoporous structure to an approximately non-porous structure by altering the reaction parameters. The well-defined mesopores, intrinsic asymmetry, and pH-dependent charge reversal characteristics enable the as-prepared mesoporous bowl-like PST nanoparticles' potential for constructing responsive biomedical nanomotors through incorporating some catalytic functional materials, 3.5 nm CeO2 nanoenzymes, as a demonstration. The constructed nanomotors demonstrate remarkable autonomous movement capabilities under physiological H2O2 concentrations, even at an extremely low concentration of 0.05 mM, showcasing the 51.58 body length/s velocity. Furthermore, they can also respond to physiological pH values ranging from 4.4 to 7.4, exhibiting reduced mobility with increasing pH. This charge reversal-based responsive nanomotor design utilizing PST nanoparticles holds great promise for advancing the application of nanomotors within complex biological systems.

The Altitudinal Dependences of the Inter‐Hemispheric Asymmetry in the Mid‐Latitude Ionospheric Post‐Midnight Enhancement During Equinox

AbstractUsing observations from multi‐satellites at different altitudes, including the CHAllenging Minisatellite Payload (CHAMP), the Gravity Recovery and Climate Experiment, Swarm B, and Defense Meteorological Satellites Program F17, the ionospheric post‐midnight enhancement at mid‐latitudes and the associated inter‐hemispheric asymmetry during equinox are investigated in this study. During equinox months, the ionospheric electron density enhancement during post‐nighttime at mid‐latitudes is visible in both hemispheres, however, it is asymmetric between the Northern and Southern Hemispheres. At most longitudes, inter‐hemispheric asymmetry of Mid‐latitude Ionospheric Post‐midnight Enhancement (MIPE) reverses with altitudes, from a stronger electron density in the Northern Hemisphere at CHAMP altitude to a stronger electron density in the Southern Hemisphere at top ionosphere during equinox. The reversal altitude and reversal time have significant longitudinal differences. The effective ionospheric uplifting induced by the combination of neutral winds and geomagnetic field configuration is the main contribution to the asymmetry reversal of MIPE at lower altitudes, as shown in the simulations from the SAMI2 and HWM14 models. In comparison with that in the Southern Hemisphere, the stronger neutral winds in the Northern Hemisphere move the plasma along the geomagnetic field lines to a higher altitude with lower chemical recombination, resulting in the enhancement of electron density.

Changes in tide-induced asymmetries in a tidal creek by the presence of intertidal flats: The San Pedro Channel (Cadiz Bay)

A two-dimensional, non-linear, finite difference, hydrodynamic model was applied to the San Pedro channel (Cadiz bay) to study the changes on tidal current asymmetries along its course due to the reconnection of its main channel to a wide tidal lagoon that was artificially desiccated in the mid of 20th century. Results of both experimental in-situ data and model simulations show changes from a flood-dominance of current asymmetries when the channel was isolated, to a stronger and ebb-directed asymmetry after the reconnection to the upper lagoon. The influence of the upstream intertidal flats is revealed on the configuration of tidal current asymmetries induced by the mutual phase-lags between the M2 and M4 tidal constituents, as well as in the tide-induced residual currents. These effects were found to be stronger during spring tides. The impacts of current asymmetry reversal on the morphodynamics of coastal tidal environments and on water quality and pollutants transport are discussed.

The differential conjugate hemisphere ionospheric response during solstice storms and the winter side maxima

The hemispheric differences in the impact of the geomagnetic storms of June 2015 and December 2015 are investigated. A meridional chain of ground observatories along 95°E ± 10°E (conjugate point-GNSS receiver/Ionosonde), satellite in-situ measurements (SWARM/COSMIC/C-NOFS), and Total Electron Content maps are utilized. Symmetric negative (positive) effects were noted during the main phase of the June (December) storm but hemispheric asymmetry was manifested during the recovery phase. The quiet time hemispheric asymmetry was reversed during both storms with positive TEC effects on the winter side. Differential VTEC and NmF2 responses exhibited seasonal variation. On 23 June 2015, the VTEC enhancements in the southern low latitude were large and consistent in contrast to the weak response in NmF2. In contrast, during the December storm, the NmF2 depletion in southern low latitude was more severe than the corresponding depletion in VTEC. The topside density/TEC enhancement in the southern low latitude recorded by SWARM was much higher than 300 % during the morning of 23 June. The SWARM Ne/TEC profile as well as the ground GPS TEC map showed a third latitudinal maximum around −45° dip angle of field lines in southern low latitudes on 23 June, in addition to the conventional EIA crests. Similarly, an early morning maximum was recorded at + 45° dip (northern hemisphere) on 21 December. The hmF2 measured by the southern hemisphere ionosonde and COSMIC satellite showed an anomalously higher altitude of the F2-layer on 23 June while C/NOFS recorded equator-ward meridional flow velocity. The reversal of the hemispheric asymmetry and the additional storm time transient maximum on the winter side is attributed to the equator-ward winds surge in the winter hemisphere due to storm time heating of the polar region.

Liposomes and Lipid Droplets Display a Reversal of Charge-Induced Hydration Asymmetry.

The unique properties of water are critical for life. Water molecules have been reported to hydrate cations and anions asymmetrically in bulk water, being a key element in the balance of biochemical interactions. We show here that this behavior extends to charged lipid nanoscale interfaces. Charge hydration asymmetry was investigated by using nonlinear light scattering methods on lipid nanodroplets and liposomes. Nanodroplets covered with negatively charged lipids induce strong water ordering, while droplets covered with positively charged lipids induce negligible water ordering. Surprisingly, this charge-induced hydration asymmetry is reversed around liposomes. This opposite behavior in charge hydration asymmetry is caused by a delicate balance of electrostatic and hydrogen-bonding interactions. These findings highlight the importance of not only the charge state but also the specific distribution of neutral and charged lipids in cellular membranes.

Enhanced EBSD calibration accuracy based on gradients of diffraction patterns

High-resolution electron backscatter diffraction (HR-EBSD) attracts increasing attention in materials researches, and correlating simulated and experimental diffraction patterns is a major HR-EBSD branch. However, the correlation accuracy is limited by several secondary effects generally not accounted for in pattern simulations, such as the non-uniform electron energy, Kikuchi band (K-band) asymmetry or gray level reversal. Although some of these phenomena can be simulated by Monte Carlo method and dynamical simulation, the computation is highly demanding and their effects on EBSD calibration are not systematically analyzed. Recently, it has been shown that the precise locations of K-band edges were better identified using the gradient of the diffraction patterns, in particular with the presence of K-band asymmetry. In the present study, it is proposed to use a similar strategy, in Integrated Digital Image Correlation to circumvent the systematic errors, and lack of accuracy due to these asymmetry artefacts. Gray level profiles of the K-bands are analyzed to assess the correctness of image registration. High-definition experimental EBSD datasets show that crystal orientation uncertainty improves by 0.01° when using gradients. Another evidence of the enhanced calibration accuracy is the improved continuity of the calibrated projection center position at grain boundaries by about 50%. In view of these results, it is suggested to systematically use gradients of diffraction patterns in all high-resolution EBSD analyses when correlating experimental and simulated patterns.

Spin- and angle-resolved photoemission spectroscopy study of heptahelicene layers on Cu(111) surfaces.

It has been demonstrated previously that electrons interact differently with chiral molecules depending on their polarization. For enantiomeric pure monolayers of heptahelicene, opposite asymmetries in spin polarization were reported and attributed to the so-called chirality-induced spin selectivity effect. However, these promising proof-of-concept photoemission experiments lack the angular and energy resolution that could provide the necessary insights into the mechanism of this phenomenon. In order to fill in the missing gaps, we provide a detailed spin- and angle-resolved photoemission spectroscopy study of heptahelicene layers on a Cu(111) substrate. Throughout the large accessible energy and angle range, no chirality induced spin asymmetry in photoemission could be observed. Possible reasons for the absence of signatures of the spin-dependent electron transmission through the chiral molecular layer are briefly discussed.

Asymmetry Between Positive and Negative Phases of the Pacific Meridional Mode: A Contributor to ENSO Transition Complexity

AbstractThe Pacific Meridional Mode (PMM) plays a critical role in affecting El Niño‐Southern Oscillation (ENSO). This study examines the phase asymmetry of PMM events triggered by tropical and extratropical forcings, namely successive and stochastic events, respectively. It is shown that successive events exhibit negative asymmetry due to stronger trigger in the negative phase, while stochastic events display positive asymmetry due to stronger growth in the positive phase. The opposite phase asymmetry of two types of events respectively results in more frequent persistent La Niña events than El Niño events and more frequent episodic El Niño events than La Niña events, which increase ENSO transition complexity. This research provides a comprehensive understanding of PMM asymmetry and reconciles conflicting perspectives from previous studies. Additionally, the newly proposed contribution of positively asymmetric stochastic PMM events to more frequent episodic El Niño events in this study may enhance our comprehension of ENSO transition complexity.

Control of Andreev Bound States Using Superconducting Phase Texture.

Andreev bound states with opposite phase-inversion asymmetries are observed in local tunneling spectra at the two ends of a superconductor-semiconductor-superconductor planar Josephson junction in the presence of a perpendicular magnetic field, while the nonlocal spectra remain phase symmetric. Spectral signatures agree with a theoretical model, yielding a physical picture in which phase textures in superconducting leads localize and control the position of Andreev bound states in the junction, demonstrating a simple means of controlling the position and size of Andreev states within a planar junction.

Comparative analysis of the two suborders of Thysanoptera and characterization of the complete mitochondrial genome of Thrips parvispinus.

Thrips parvispinus is a serious sucking pest on a number of economically important crops in the oriental region. It has gained importance recently for its drastic range extension distribution as an invasive pest. Here, the complete mitochondrial genome (15,067 bp) of Thrips parvispinus was sequenced and characterized. It possesses 37 genes and the putative noncoding region is duplicated. Comparative analyses of nucleotide diversity, skewness, codon usage bias, and selection pressure in mitochondrial protein-coding genes of the available 31 thrips mitogenomes (24 Terebrantia + 7 Tubulifera) were performed. Phylogenetic analysis showed a sister relationship of T. parvispinus to the clade (T. florum + T. hawaiiensis). Phylogenetic analyses formed the monophyly of subfamilies Phlaeothripinae and Idolothripinae within the family Phlaeothripidae (Suborder Tubulifera). Low nucleotide diversity was indicative of reversal of strand asymmetry in the Tubulifera. Neutrality analysis showed that directional mutation plays a major role in shaping codon usage bias in both suborders. Principal component analysis indicated distinct codon usage patterns in each suborder. Our data suggested weaker selection constrains on Terebrantia than in the Tubulifera. More tubuliferan mitogenomes are required to resolve previous classification hypotheses and elucidate genome evolution in these two suborders.

Should I have been more careful or less careless? The comparative nature of counterfactual thoughts alters judgments of their impact

Counterfactual thoughts inherently imply a comparison of a given reality to an alternative state of affairs. Previous research mainly considered consequences of different counterfactual types, namely focus (other vs. self), structure (additive vs. subtractive), and direction (upward vs. downward). The current work investigates whether a ‘more-than’ versus ‘less-than’ comparative nature of counterfactual thoughts alters judgments of their impact. Four experiments demonstrated that self-generated other- (Studies 1 and 3) and self-focused (Study 2) upward counterfactuals are judged more impactful when they entail ‘more-than’ rather than ‘less-than’ comparisons. Judgments include plausibility and persuasiveness, as well as counterfactuals' likelihood to change future behavior and feelings. Self-reported ease of thought generation and (dis)fluency gauged by difficulty in thought generation was similarly affected. This more-less asymmetry reversed in Study 3 for downward counterfactual thoughts, with ‘less-than’ counterfactuals being judged more impactful and easier to generate. Further attesting to the role of ease, when spontaneously generating comparative counterfactuals, participants correctly provided more ‘more-than’ upward counterfactuals, but more ‘less-than’ downward counterfactuals (Study 4). These findings delineate one of the to date few conditions for a reversal of the more-less asymmetry and provide support for a correspondence principle, the simulation heuristic, and thus the role of ease in counterfactual thinking. They suggest that especially ‘more-than’ counterfactuals following negative events, and ‘less-than’ counterfactuals following positive events, are likely to have an important impact on people. (226 words)

Deformation mechanisms of dual-textured Mg-6.5Zn alloy with limited tension-compression yield asymmetry

A dual-textured wrought Mg-6.5 Zn (wt.%) alloy with limited yield asymmetry (compressive yield strength / tensile yield strength: 0.90) is reported. Approximately 80% of the grains present the standard texture of wrought Mg alloys while the grain orientation is rotated by ≈ 90º perpendicularly to the c axis in the remaining 20%. The deformation mechanisms responsible for this behavior are analyzed on samples deformed in tension and compression up to different strains. Compressive deformation of the grains with the standard texture is accommodated by 〈a〉 basal slip and extension twinning while tensile deformation promotes 〈a〉 basal and non-basal 〈a〉 prismatic and 〈a〉 pyramidal slip, leading to the typical yield asymmetry. However, the rotated grains present the opposite (and much stronger) yield asymmetry because tensile deformation is absorbed by 〈a〉 basal slip and extension twinning while compression deformation requires 〈a〉 basal slip and compression twinning. Thus, the contribution of the 20% rotated grains to the overall mechanical behavior leads to (almost) similar values of the yield strength in tension and compression. This work provides a physical understanding of the deformation behavior of dual-textured Mg alloys, that can be used to develop novel dual-textured Mg alloys with limited yield asymmetry.

Cognitive mechanisms underlying subjective value of past and future events: Modeling systematic reversals of temporal value asymmetry.

Cognitive mechanisms underlying subjective value of past and future events: Modeling systematic reversals of temporal value asymmetry.

Voltage waveform tailoring for high aspect ratio plasma etching of SiO2 using Ar/CF4/O2 mixtures: Consequences of ion and electron distributions on etch profiles

The quality of high aspect ratio (HAR) features etched into dielectrics for microelectronics fabrication using halogen containing low temperature plasmas strongly depends on the energy and angular distribution of the incident ions (IEAD) onto the wafer, as well as potentially that of the electrons (EEAD). Positive ions, accelerated to high energies by the sheath electric field, have narrow angular spreads and can penetrate deeply into HAR features. Electrons typically arrive at the wafer with nearly thermal energy and isotropic angular distributions and so do not directly penetrate deeply into features. These differences can lead to positive charging of the insides of the features that can slow etching rates and produce geometric defects such as twisting. In this work, we computationally investigated the plasma etching of HAR features into SiO2 using tailored voltage waveforms in a geometrically asymmetric capacitively coupled plasma sustained in an Ar/CF4/O2 mixture at 40 mTorr. The tailored waveform consisted of a sinusoidal wave and its higher harmonics with a fundamental frequency of 1 MHz. We found that some degree of control of the IEADs and EEADs is possible by adjusting the phase of higher harmonics φ through the resulting generation of electrical asymmetry and electric field reversal. However, the IEADs and EEADs cannot easily be separately controlled. The control of IEADs and EEADs is inherently linked. The highest quality feature was obtained with a phase angle φ = 0° as this value generated the largest (most negative) DC self-bias and largest electric field reversal for accelerating electrons into the feature. That said, the consequences of voltage waveform tailoring (VWT) on etched features are dominated by the change in the IEADs. Although VWT does produce EEADs with higher energy and narrower angular spread, the effect of these electrons on the feature compared to thermal electrons is not large. This smaller impact of VWT produced EEADs is attributed to thermal electrons being accelerated into the feature by electric fields produced by the positive in-feature charging.