Diffuse Component Research Articles

Identification of the inhibitory mechanism of ecumicin and rufomycin 4-7 on the proteolytic activity of Mycobacterium tuberculosis ClpC1/ClpP1/ClpP2 complex

Ecumicin and rufomycin 4-7 disrupt protein homeostasis in Mycobacterium tuberculosis by inhibiting the proteolytic activity of the ClpC1/ClpP1/ClpP2 complex. Although these compounds target ClpC1, their effects on the ATPase activity of ClpC1 and proteolytic activity of ClpC1/ClpP1/ClpP2 vary. Herein, we explored the ClpC1 molecular dynamics with these compounds through fluorescence correlation spectroscopy. The effect of these compounds on the ATPase activity of ClpC1-cys, the recombinant protein for fluorescence labeling, and proteolytic activity of ClpC1-cys/ClpP1/ClpP2 were identical to those of native ClpC1, whereas the intermolecular dynamics of fluorescence-labelled ClpC1 were different. Treatment with up to 1 nM ecumicin increased the population of slower diffused ClpC1 components compared with ClpC1 without ecumicin. However, this population was considerably reduced when treated with 10 nM ecumicin. Rufomycin 4-7 treatment resulted in a slower diffused component of ClpC1, and the portion of this component increased in a concentration-dependent manner. Ecumicin can generate an abnormal ClpC1 component, which cannot form normal ClpC1/ClpP1/ClpP2, via two different modes. Rufomycin 4-7 only generates slower diffused ClpC1 component that is inadequate to form normal ClpC1/ClpP1/ClpP2. Overall, we demonstrate that ecumicin and rufomycin 4-7 use different action mechanisms to generate abnormal ClpC1 components that cannot couple with ClpP1/ClpP2.

Modelling multiphase gases in cosmological simulations using compressible multifluid hydrodynamics

ABSTRACT The diffuse medium in and around galaxies can exist in a multiphase state: small, cold gas clouds contributing significantly to the total mass embedded in pressure equilibrium with a hotter, more diffuse volume-filling component. Modelling this multiphase state in cosmological simulations poses a significant challenge due to the requirements to spatially resolve the clouds and consequently the interactions between the phases. In this paper, we present a novel method to model this gas state in cosmological hydrodynamical simulations. We solve the compressible two-fluid hydrodynamic equations using a moving-mesh finite-volume method and define mass, momentum, and energy exchange terms between the phases as operator-split source terms. Using a stratified flow model, our implementation is able to maintain volume fraction discontinuities in pressure equilibrium to machine precision, allowing for the treatment of both resolved and unresolved multiphase fluids. The solver remains second order accurate on smooth hydrodynamics problems. We use the source and sink terms of an existing two-phase model for the interstellar medium to demonstrate the value of this type of approach in simulations of galaxy formation, compare it to its effective equation of state implementation, and discuss its advantages in future large-scale simulations of galaxy formation.

Improved esthetic efficacy and reduced cytotoxicity are achieved with a violet LED irradiation of manganese oxide-enriched bleaching gels.

Gels with high concentrations of hydrogen peroxide (H2O2) have been associated with cytotoxicity and consequent post-bleaching tooth sensitivity. This study assessed the bleaching efficacy (BE) and cytotoxicity (CT) of bleaching gels with low concentrations of H2O2 containing manganese oxide (MnO2) and photocatalyzed with violet LED (LEDv). The following groups were established: G1: no treatment (negative control, NC); G2: 35% H2O2 (positive control, PC); G3: LEDv; G4: 10% H2O2; G5: 6% H2O2; G6: 10% H2O2 + MnO2 + LEDv; G7: 6% H2O2 + MnO2 + LEDv. To analyze BE, standardized enamel/dentin discs (E/DDs) were subjected to the bleaching procedures for 45min (1 session). The color change was determined before and after performing the bleaching protocols (ΔE00; ΔWI). To analyze CT, the E/DDs were adapted to artificial pulp chambers, and the extracts (culture medium + diffused gel components) were applied to cultured odontoblast-like MDPC-23 cells. Then, the cells were assessed concerning their viability (VB), oxidative stress (OxS), and Live/Dead. The amount of H2O2 diffused was also determined (ANOVA/Tukey; p < 0.05). Cell viability decreased in all bleached groups compared to G1 (NC; p < 0.05). The cells in G6 and G7 presented higher viability than in G2, G4, and G5 (p < 0.05). The BE in G7 was similar to G2 (PC; p < 0.05). The lowest OxS and H2O2 diffusion values were found in G6 and G7, compared to the other bleached groups (G2, G4, and G5; p < 0.05). The 6% H2O2 bleaching gel (G7) submitted to both methods of catalysis (MnO2 + LEDv) caused only a mild cytotoxicity and maintained the excellent esthetic outcome promoted by in-office conventional tooth bleaching.

Architected Low-Tortuosity Electrodes with Tunable Porosity from Nonequilibrium Soft-Matter Processing.

Mass transport is performance-defining across energy storage devices, often causing limitations at high current rates. To optimize and balance the device-scale energy and power density for a given energy storage demand, tailored electrode architectures with precisely controllable phase dimensions are needed in combination with low-tortuosity channels that maximize the geometric component of diffusion and species flux. A material-agnostic nonequilibrium soft-matter process is reported to fabricate free-standing inorganic composite electrodes with adjustable thicknesses of 100s ofµm, featuring straight and accessible channels ranging in diameter from 5-30µm, coupled with tunable material-to-pore ratios. Such architected anode and cathode electrodes exhibit electrochemical and architectural stability over extended cycling in a full-cell battery. Further, mass-transport constraints appear at high current densities, and the lithiation step is identified as rate-performance limiting, a result of insufficient lithium-ion supply and concentration polarization. The results demonstrate the need for and feasibility of tailored electrode architectures where dimensional ratios between low-tortuosity channels, the charge-storing matrix, and electrode thickness are tunable to meet coupled power and energy-storage requirements.

Baryon pasting algorithm: halo-based and particle-based pasting methods

ABSTRACT We present a fast methodology to produce mock observations of the thermal and kinetic Sunyaev–Zel’dovich (SZ) effects based on the dark matter only N-body simulations coupled with the analytic intracluster medium model. The methods employ two different approaches: halo-based pasting (HP) and particle-based pasting (PP). The former pastes gas density and pressure on to haloes and requires only a halo catalogue, and the latter considers the contribution from field particles as well, i.e. particles that do not belong to any haloes and thus utilize the full particle information. Therefore, the PP algorithm incorporates secondary effects beyond the HP algorithm: asphericity of haloes and contribution from diffuse gas. In particular, such a diffuse component is the dominant source of the kinetic SZ effect. As validation of our methods, we have produced 108 all-sky maps with HP and 108 flat-sky maps, which cover $5 \times 5 \, \mathrm{deg}^2$ with both HP and PP, and measured power spectra of the maps. Our method can produce a mock map within a few hours, even for all-sky coverage with a parallel computational environment. The power spectra of HP maps are consistent with the halo model prediction of the thermal SZ effect. On the other hand, the power spectra of PP maps are suppressed due to the halo asphericity but can reproduce better the theoretical prediction for the kinetic SZ effect. We discuss the utility of baryon-pasted mock SZ maps for estimating the covariance matrix of SZ statistics and modelling the selection and projection effects for cluster cosmology.

Assessing the impacts of anthropogenic sounds on early stages of benthic invertebrates: The “Larvosonic system”

AbstractNoise produced by human activities has increased in the oceans over the last decades. Whereas most studies have focused on the impact of anthropogenic noise on marine mammals and fishes, those focusing on marine invertebrates are rarer and more recent, especially when considering peri‐metamorphic benthic stages, highly sensitive to anthropogenic perturbations. A careful review of the literature reveals a simplistic characterization of the acoustics within the containers used to quantify larval and juvenile responses to noise, thus weakening the conclusions of such works. To address this problem, we developed the Larvosonic system, a laboratory tank equipped with acoustic assets to assess the impacts of noise on young stages of marine invertebrates. We first provide a careful analysis of the tank sound field using different sound types, and we assess the effects of expanded polystyrene units on the sounds emitted by a professional audio system in order to dampen reverberation and resonance. Then, we apply this acoustic calibration to the effects of both pile driving and drilling noises on postlarvae of the scallop bivalve Pecten maximus. Acoustic recordings highlight that diffuser and bass trap components constitute effective underwater sound absorbents, reducing the reflection of the whole frequency bandwidth. Scallop experiments reveal that both type and level of the tested noise influenced postlarval growth, with interactive effects between trophic environment and noise level/spectra. The Larvosonic system thus constitutes an efficient tool for bioacoustics research on bentho‐planktonic invertebrate species.

The interplay of active and passive mechanisms in slow axonal transport

A combination of intermittent active movement of transient aggregates and a paused state that intervenes between periods of active transport has been proposed to underlie the slow, directed transport of soluble proteins in axons. A component of passive diffusion in the axoplasm may also contribute to slow axonal transport, although quantitative estimates of the relative contributions of diffusive and active movement in the slow transport of a soluble protein, and in particular how they might vary across developmental stages, are lacking. Here, we propose and study a model for slow axonal transport, addressing data from bleach recovery measurements on a small, soluble, protein, choline acetyltransferase, in thin axons of the lateral chordotonal (lch5) sensory neurons of Drosophila. Choline acetyltransferase is mainly present in soluble form in the axon and catalyzes the acetylation of choline at the synapse. It does not form particulate structures in axons and moves at rates characteristic of slow component b (≈ 1–10 mm/day or 0.01–0.1 μm/s). Using our model, which incorporates active transport with paused and/or diffusive states, we predict bleach recovery, transport rates, and cargo trajectories obtained through kymographs, comparing these with experimental observations at different developmental stages. We show that changes in the diffusive fraction of cargo during these developmental stages dominate bleach recovery and that a combination of active motion with a paused state alone cannot reproduce the data. We compared predictions of the model with results from photoactivation experiments. The importance of the diffusive state in reproducing the bleach recovery signal in the slow axonal transport of small soluble proteins is our central result.

Extended radio emission in the galaxy cluster MS 0735.6+7421 detected with the Karl G. Jansky Very Large Array

ABSTRACT MS 0735.6+7421 (z = 0.216) is a massive cool core galaxy cluster hosting one of the most powerful active galactic nuclei (AGNs) outbursts known. The radio jets of the AGN have carved out an unusually large pair of X-ray cavities, each reaching a diameter of 200 kpc. This makes MS 0735.6+7421 a unique case to investigate active galactic nuclei feedback processes, as well as other cluster astrophysics at radio wavelengths. We present new low radiofrequency observations of MS 0735.6+7421 taken with the Karl G. Jansky Very Large Array (VLA): 5 h of P-band (224–480 MHz) and 5 h of L-band (1–2 GHz) observations, both in C configuration. Our VLA P-band (224–480 MHz) observations reveal the presence of a diffuse radio component reaching a scale of ≈ 900 kpc in the direction of the jets and of ≈ 500 kpc in the direction perpendicular to the jets. This component is centred on the cluster core and has a radio power scaled at 1.4 GHz of P1.4GHz = (4 ± 2) × 1024 W Hz−1. Its properties are consistent with those expected from a radio minihalo as seen in other massive cool core clusters, although it may also be associated with radio plasma that has diffused out of the X-ray cavities, or to a combination of these two hypotheses. Observations at higher spatial resolution are needed to fully characterize the properties and nature of this component. We also suggest that if radio minihaloes originate from jetted activity, we may be witnessing the early stages of this process.

Ідентифікація координат імпульсних джерел числовими методами квазіконформних відображень

The process of convective transfer of substances during filtration in a po-rous medium (horizontal layer) is considered. An approach to determining the coordinates and action time of a special typeof impulse sources (pollution, heat, explosion, etc.) is proposed, based on the assumption that the latter have no significant effect on the filtration background. For identification, infor-mation about the trajectories (which coincide with the flow lines)of the movement of the impurity substance and the time intervals of the flow of pol-lution from their sources to the corresponding places (points) of observation (detection) is used. It is proposed to identify the coordinates of point sources using characteristic (in relation to the convection equation) functions, a priori information about the movement of pollution, and given coordinates of the nodes of the constructed hydrodynamic mesh. Significant simplifications for the process of constructing the solving algorithm are achieved by replacing the existing model problem of finding the functions of the quasipotential and the flow in complex by the corresponding inverse problem (which, among other things, provides the possibility of effectively constructing ahydrodynamic motion mesh). Its solution is based on the procedure of quasiconformal map-ping of the corresponding quadrangular complex quasipotential domain into a given physical domain. Numerical experiments are presented and analyzed. In particular, it was found that the accuracy of identification of pollution sources depends significantly on the available values of quasiconformity residuals. Their greatest values are achieved on those flow lines that pass through char-acteristic points (so-called «key points») or near stagnant zones. It is possible to reduce the errors generated by the latter, in particular, with a large number of partition nodes. The developed algorithm provides opportunities for its fur-ther transfer to more complex cases of fluid motion,in particular, with addi-tional consideration of the diffusion component, generalization to space, etc.

Interdiffusivity matrices and atomic mobilities in fcc Co–Ni–Si and Cu–Co–Ni–Si alloys: Experiment and modeling

Accurate diffusion kinetics information of fcc Co–Ni–Si alloys is essential for developing high-performance Cu–Co–Ni–Si alloys. Eight diffusion couples at the Co–Ni side are assembled to determine the Co- and Ni-basis diffusivities of fcc Co–Ni–Si alloys at 1273 or 1373 K. The diffusivity matrices at the intersection compositions of diffusion paths are determined by the Matano-Kirkaldy method. In addition, the diffusivity matrices along the whole composition profiles and the atomic mobilities of fcc Co–Ni–Si alloys are evaluated by the numerical inverse approach. The reliability of the obtained atomic mobilities is verified by comparing the predicted diffusion phenomena with the experimental ones. Strong cross phenomenon effects among the components are manifested by large negative cross diffusivities, the development of zero flux planes and uphill diffusion phenomena. The uphill diffusion in the fcc Co–Ni–Si system is due to the cross phenomenon between diffusion components. The location of the zero flux plane of a component is usually the intersection between the diffusion path and the iso-activity line for that component through a terminal alloy. Combining the mobility descriptions of the fcc Co–Ni–Si system with the other three sub-ternary systems in the literature, the atomic mobilities in fcc Cu–Co–Ni–Si alloys are constructed. The model-predicted composition profiles of Cu–Co–Ni–Si alloys show a good agreement with the experimental ones, validating the accuracy of the obtained atomic mobilities.

Quantifying the Spectral Diffusion of N- V Centers by Symmetry

The spectrally narrow, spin-dependent optical transitions of nitrogen-vacancy (N-$V$) center defects in diamond can be harnessed for quantum networking applications. Key to such networking schemes is the generation of indistinguishable photons. Two challenges limit scalability in such systems: defect-to-defect variations of the optical transition frequencies caused by local strain variation, and spectral diffusion of the optical frequencies on repeated measurement caused by photoexcitation of nearby charge traps. In this experimental study we undertake a group-theoretic approach to quantifying spectral diffusion and strain, decomposing each into components corresponding to Jahn-Teller symmetries of the N-$V$ center. We investigate correlations between the components of strain, spectral diffusion, and depth from the surface, finding that strain and spectral diffusion are each dominated by longitudinal perturbations. We also find a weak negative correlation between transverse static strain and total spectral diffusion, suggesting that transverse strain provides some degree of protection from spectral diffusion. Additionally, we find that spectral diffusion becomes more pronounced with increasing depth in the diamond bulk. Our symmetry-decomposed technique for quantifying spectral diffusion can be valuable for understanding how a given nanoscale charge trap environment influences spectral diffusion and for developing strategies of mitigation.

The Impact of Beam Variations on Power Spectrum Estimation for 21 cm Cosmology. I. Simulations of Foreground Contamination for HERA

Detecting cosmological signals from the Epoch of Reionization (EoR) requires high-precision calibration to isolate the cosmological signals from foreground emission. In radio interferometry, the perturbed primary beams of antenna elements can disrupt the precise calibration, which results in the contamination of the foreground-free region, or the EoR window, in the cylindrically averaged power spectrum. For the Hydrogen Epoch of Reionization Array (HERA), we simulate and characterize the perturbed primary beams that are induced by feed motions, such as axial, lateral, and tilting motions, above the 14 m dish. To understand the effect of the perturbed beams, visibility measurements are modeled with two different foreground components, point sources and diffuse sources, and we find that different feed motions present a different reaction to each type of sky source. HERA’s redundant baseline calibration in the presence of nonredundant antenna beams due to feed motions introduces chromatic errors in the gain solutions, producing foreground power leakage into the EoR window. The observed leakage from the vertical feed motions comes predominantly from point sources around the zenith. Furthermore, the observed leakage from the horizontal and tilting feed motions comes predominantly from the diffuse components near the horizon. Mitigation of the chromatic gain errors will be necessary for robust detections of the EoR signals with minimal foreground bias, and this will be discussed in a subsequent paper.

Ante mortem imaging of cortical microstructure relates to post mortem locus coeruleus hypopigmentation in autopsy‐confirmed Alzheimer’s disease

AbstractBackgroundSeveral lines of evidence indicate that Locus Coeruleus (LC) abnormalities occur early in Alzheimer’s disease and are linked to tau pathology. However, the mechanisms underlying alterations in LC structure and function, and their contributions to pathogenesis and disease progression remain unclear. We investigate ante mortem cortical microstructural changes in patients with autopsy‐confirmed Alzheimer’s disease neuropathological changes (ADNC), stratified by Locus Coeruleus hypopigmentation (LCh).MethodParticipants with intermediate or severe ADNC and ante mortem MRI were obtained from the National Alzheimer's Coordinating Center (NACC; n=29) and the Alzheimer's Disease Neuroimaging Initiative (ADNI; n=6). Participants were grouped by LCh severity (15 with none/mild and 20 moderate/severe).Structural and diffusion MRI (dMRI) were used to calculate cortical mean diffusivity and three novel cortical diffusivity measures, at whole‐brain and regional levels: the angle between the radial minicolumnar direction and the principal diffusion direction (AngleR); the principal diffusion component parallel with the minicolumns (ParlPD), and the diffusion components perpendicular to the minicolumns (PerpPD+).Clinical, demographic and MRI data were used to characterize groups. Group differences in diffusion metrics were tested with a linear model, adjusting for age, interval between scan and date of death, site‐ID, number of dMRI images, and diffusion b‐value, with false discovery rate correction (pFDR&lt;0.05).ResultThe more severe LCh group was significantly younger; no significant differences were detected for cortical or hippocampal volumes, cortical thickness, CDR or MMSE. At whole‐brain level, more severe LCh exhibited significantly higher PerpPD and ParlPD. The regional investigation revealed a widespread pattern of higher PerpPD, while ParlPD showed significantly higher values mainly in parieto‐occipital regions (Figure1).ConclusionTogether, these findings suggest that LCh severity might contribute to different patterns of cortical microstructural changes in individuals with the same ADNC severity. The more severe LCh group was significantly younger, consistent with the idea that noradrenergic hyperactivity in a more impaired LC might accelerate the spreading of AD neuropathology due to an influence of noradrenergic projections (Weinshenker, 2018). Cortical microstructural measures from dMRI could help stratify patients in clinical trials based on patterns linked to noradrenergic dysfunction, supporting pharmacological treatment focused on hyperactivities of the noradrenergic system.

Regional pattern of cortical microstructural alterations along the AD continuum and association with plasma neurofilament light

AbstractBackgroundMicrostructural changes associated with the progression of Alzheimer's disease (AD) precede macrostructural atrophy. We investigate cortical microstructural changes along the AD continuum in patients with cerebrospinal fluid (CSF) AD biomarkers and plasma neurofilament light chain (NfL).MethodThree hundred fifty‐one participants from the Alzheimer's Disease Neuroimaging Initiative (ADNI) with CSF amyloid‐beta 42 (Aβ42) and Phosphorylated Tau 181 (pTau181) were included. The CSF pTau181‐Aβ42 ratio was used to assess the presence (+/‐) of the pathophysiological hallmarks of AD and classify the participants into four groups: 149 cognitively normal biomarker negative (CN‐), 61 cognitively normal positive (CN+), 73 patients diagnosed with Mild Cognitive Impairment positive (MCI+) and 68 AD positive (AD+).Structural and diffusion MRI (dMRI) were used to calculate cortical mean diffusivity and three novel cortical diffusivity measures: the angle between the radial minicolumnar direction and the principal diffusion direction (AngleR); the principal diffusion component parallel with the minicolumns (ParlPD), and the diffusion components perpendicular to the minicolumns (PerpPD+).Clinical, demographic and MRI data were used to characterize groups. Group differences in diffusion metrics were tested with a linear model, adjusting for age, sex and site‐ID, with false discovery rate correction (pFDR&lt;0.05). The association between cortical diffusivity and NfL was investigated in a subset of 111 participants.ResultAt whole‐brain level, the AD+ group exhibited significantly higher AngleR, PerpPD+, ParlPD and MD values compared to the other groups. PerpPD+ was the only measure able to differentiate between all subsequent disease stages (CN‐ and CN+ vs MCI+, and MCI+ vs AD+); regional results are presented in the Figure. Along the AD continuum, the results revealed a widespread progressive pattern of higher PerpPD+, involving mainly fronto‐temporal and occipital regions. Correlation analysis showed significant association between cortical diffusivity measures (PerpPD+ and ParlPD) and NfL values.ConclusionCortical diffusivity measures can detect progressive microstructural changes along the AD continuum and are significantly associated with NfL. Cortical diffusion MRI offers a microstructural marker of neurodegeneration within the ATN framework (Jack et al. 2018); as an imaging measure, regional patterns can provide disease specificity that is lacking for fluid measures like NfL.

Ante mortem imaging of cortical microstructure relates to post mortem locus coeruleus hypopigmentation in autopsy‐confirmed Alzheimer’s disease

AbstractBackgroundSeveral lines of evidence indicate that Locus Coeruleus (LC) abnormalities occur early in Alzheimer’s disease and are linked to tau pathology. However, the mechanisms underlying alterations in LC structure and function, and their contributions to pathogenesis and disease progression remain unclear. We investigate ante mortem cortical microstructural changes in patients with autopsy‐confirmed Alzheimer’s disease neuropathological changes (ADNC), stratified by Locus Coeruleus hypopigmentation (LCh).MethodParticipants with intermediate or severe ADNC and ante mortem MRI were obtained from the National Alzheimer's Coordinating Center (NACC; n=29) and the Alzheimer's Disease Neuroimaging Initiative (ADNI; n=6). Participants were grouped by LCh severity (15 with none/mild and 20 moderate/severe).Structural and diffusion MRI (dMRI) were used to calculate cortical mean diffusivity and three novel cortical diffusivity measures, at whole‐brain and regional levels: the angle between the radial minicolumnar direction and the principal diffusion direction (AngleR); the principal diffusion component parallel with the minicolumns (ParlPD), and the diffusion components perpendicular to the minicolumns (PerpPD+).Clinical, demographic and MRI data were used to characterize groups. Group differences in diffusion metrics were tested with a linear model, adjusting for age, interval between scan and date of death, site‐ID, number of dMRI images, and diffusion b‐value, with false discovery rate correction (pFDR&lt;0.05).ResultThe more severe LCh group was significantly younger; no significant differences were detected for cortical or hippocampal volumes, cortical thickness, CDR or MMSE. At whole‐brain level, more severe LCh exhibited significantly higher PerpPD and ParlPD. The regional investigation revealed a widespread pattern of higher PerpPD, while ParlPD showed significantly higher values mainly in parieto‐occipital regions (Figure1).ConclusionTogether, these findings suggest that LCh severity might contribute to different patterns of cortical microstructural changes in individuals with the same ADNC severity. The more severe LCh group was significantly younger, consistent with the idea that noradrenergic hyperactivity in a more impaired LC might accelerate the spreading of AD neuropathology due to an influence of noradrenergic projections (Weinshenker, 2018). Cortical microstructural measures from dMRI could help stratify patients in clinical trials based on patterns linked to noradrenergic dysfunction, supporting pharmacological treatment focused on hyperactivities of the noradrenergic system.

Regional pattern of cortical microstructural alterations along the AD continuum and association with plasma neurofilament light

AbstractBackgroundMicrostructural changes associated with the progression of Alzheimer's disease (AD) precede macrostructural atrophy. We investigate cortical microstructural changes along the AD continuum in patients with cerebrospinal fluid (CSF) AD biomarkers and plasma neurofilament light chain (NfL).MethodThree hundred fifty‐one participants from the Alzheimer's Disease Neuroimaging Initiative (ADNI) with CSF amyloid‐beta 42 (Aβ42) and Phosphorylated Tau 181 (pTau181) were included. The CSF pTau181‐Aβ42 ratio was used to assess the presence (+/‐) of the pathophysiological hallmarks of AD and classify the participants into four groups: 149 cognitively normal biomarker negative (CN‐), 61 cognitively normal positive (CN+), 73 patients diagnosed with Mild Cognitive Impairment positive (MCI+) and 68 AD positive (AD+).Structural and diffusion MRI (dMRI) were used to calculate cortical mean diffusivity and three novel cortical diffusivity measures: the angle between the radial minicolumnar direction and the principal diffusion direction (AngleR); the principal diffusion component parallel with the minicolumns (ParlPD), and the diffusion components perpendicular to the minicolumns (PerpPD+).Clinical, demographic and MRI data were used to characterize groups. Group differences in diffusion metrics were tested with a linear model, adjusting for age, sex and site‐ID, with false discovery rate correction (pFDR&lt;0.05). The association between cortical diffusivity and NfL was investigated in a subset of 111 participants.ResultAt whole‐brain level, the AD+ group exhibited significantly higher AngleR, PerpPD+, ParlPD and MD values compared to the other groups. PerpPD+ was the only measure able to differentiate between all subsequent disease stages (CN‐ and CN+ vs MCI+, and MCI+ vs AD+); regional results are presented in the Figure. Along the AD continuum, the results revealed a widespread progressive pattern of higher PerpPD+, involving mainly fronto‐temporal and occipital regions. Correlation analysis showed significant association between cortical diffusivity measures (PerpPD+ and ParlPD) and NfL values.ConclusionCortical diffusivity measures can detect progressive microstructural changes along the AD continuum and are significantly associated with NfL. Cortical diffusion MRI offers a microstructural marker of neurodegeneration within the ATN framework (Jack et al. 2018); as an imaging measure, regional patterns can provide disease specificity that is lacking for fluid measures like NfL.

Автоматизоване розпаралелювання програми моделювання внутрішньочастинкової дифузії й абсорбції в неоднорідних нанопористих середовищах

Heterogeneous media consisting of thin layers of particles of forked porous structure with different physical-chemical properties are widely used in science-intensive technologies and priority sectors of industry, medicine, ecology, etc. Such layers are distributed systems of pores consisting of two main spaces: micro- and nanopores of particles and macropores and cavities between particles. Mass transfer in the system of heterogeneous media causes two types of mass transfer: diffusion in macropores, owing to interparticle space, and diffusion in the system of micro- and nanopores inside particles of the heterogeneous medium. Intraparticle space has a higher level of adsorptive capacity, and at the same time, has a lower velocity of diffusion intrusion in comparison with interparticle space. In modeling concentra- tion and gradient fields for various diffusible components, an important scientific problem is the identification of kinetic parameters of a transfer, predetermining mass transfer velocity on macro- and micro levels, and also equilibrium conditions. The results of designing and parallelization of a program implementing a Crank-Nicolson scheme using algebra-algorithmic specifications represented in a natural- linguistic form are given. The tools for automated design, synthesis and auto-tuning of programs were applied that provided the translation of algebra-algorithmic schemes into source code in a target programming language and its tuning for execution environment to increase the program performance. Numerical distributions of values of diffusion coefficients for intraparticle transfer along coordinate of medium thickness for various time snapshots were obtained. Based on the results of the identification, the models were checked for adequacy and numerical modeling and analysis of concentration and gradient fields of mass transfer were carried out. The experiment results of auto- tuning the software implementation demonstrated high multiprocessor speedup on test data input.

ШИРОКОПОЛОСНЫЙ РЕФЛЕКТОМЕТРИЧЕСКИЙ МЕТОД ИЗМЕРЕНИЯ ВЛАЖНОСТИ И СТЕПЕНИ ШЕРОХОВАТОСТИ ПОВЕРХНОСТИ ПОЧВЫ

In this article, a numerical-analytical model of the reflection coefficient of an electromagnetic wave from a rough soil surface is proposed. Based on the created model of reflection coefficient, in the frequency range from 520 MHz to 1.26 GHz, a broadband method for the root-mean-square deviation (RMS) of heights and volumetric moisture of rough soil surface is developed. When the model of reflection coefficient creating, the field of reflected wave from the rough soil surface was presented as the sum of secondary fields from an infinite set of elementary horizontal scattering plates (with a given average size). The field from each elementary scattering plate is represented as an average field from the result of stochastic interference of an infinite set of coherent elementary sources of secondary waves. The vertical position of the elementary sources is determined by the stochastic height of the soil surface within elementary plate. It is shown that the created model describes the total value of reflection coefficient (coherent and diffuse components) with the determination coefficient of R2=0.981 and root-mean square error (RMSE) no more than 0.35 dB, relative to the reflection coefficient, calculated by the finite difference method and the advanced integral equations method. The possibility of RMS heights and volumetric moisture of rough soil surface retrieval, relative to the true values, was shown no worse than R2=0.909 (RMSE=0.4 cm) and R2=0.975 (RMSE=2%), respectively. This analysis was carried out on the example of 16 soil samples, the complex permittivity of which was measured for a wide range of dry bulk densities from 0.7 g/cm3 to 1.8 g/cm3, moisture content, texture with variation clay content from 0% to 76% and organic matter content from 0.6% to 6.9%. The results have a wide application value both for single-frequency and multi-frequency radar and radiometric methods of soil moisture measuring.

AvatarMe++: Facial Shape and BRDF Inference With Photorealistic Rendering-Aware GANs.

Over the last years, with the advent of Generative Adversarial Networks (GANs), many face analysis tasks have accomplished astounding performance, with applications including, but not limited to, face generation and 3D face reconstruction from a single "in-the-wild" image. Nevertheless, to the best of our knowledge, there is no method which can produce render-ready high-resolution 3D faces from "in-the-wild" images and this can be attributed to the: (a) scarcity of available data for training, and (b) lack of robust methodologies that can successfully be applied on very high-resolution data. In this paper, we introduce the first method that is able to reconstruct photorealistic render-ready 3D facial geometry and BRDF from a single "in-the-wild" image. To achieve this, we capture a large dataset of facial shape and reflectance, which we have made public. Moreover, we define a fast and photorealistic differentiable rendering methodology with accurate facial skin diffuse and specular reflection, self-occlusion and subsurface scattering approximation. With this, we train a network that disentangles the facial diffuse and specular reflectance components from a mesh and texture with baked illumination, scanned or reconstructed with a 3DMM fitting method. As we demonstrate in a series of qualitative and quantitative experiments, our method outperforms the existing arts by a significant margin and reconstructs authentic, 4K by 6K-resolution 3D faces from a single low-resolution image, that are ready to be rendered in various applications and bridge the uncanny valley.

HyperGal: Hyperspectral scene modeling for supernova typing with the SED Machine integral field spectrograph

Context. Recent developments in time domain astronomy, such as Zwicky Transient Facility (ZTF), have made it possible to conduct daily scans of the entire visible sky, leading to the discovery of hundreds of new transients every night. Among these detections, 10 to 15 of these objects are supernovae (SNe), which have to be classified prior to cosmological use. The spectral energy distribution machine (SEDM) is a low-resolution (ℛ ~ 100) integral field spectrograph designed, built, and operated with the aim of spectroscopically observing and classifying targets detected by the ZTF main camera. Aims. As the current pysedm pipeline can only handle isolated point sources, it is limited by contamination when the transient is too close to its host galaxy core. This can lead to an incorrect typing and ultimately bias the cosmological analyses, affecting the homogeneity of the SN sample in terms of local environment properties. We present a new scene modeler to extract the transient spectrum from its structured background, with the aim of improving the typing efficiency of the SEDM. Methods. HyperGal is a fully chromatic scene modeler that uses archival pre-transient photometric images of the SN environment to generate a hyperspectral model of the host galaxy. It is based on the cigale SED fitter used as a physically-motivated spectral interpolator. The galaxy model, complemented by a point source for the transient and a diffuse background component, is projected onto the SEDM spectro-spatial observation space and adjusted to observations, and the SN spectrum is ultimately extracted from this multi-component model. The full procedure, from scene modeling to transient spectrum extraction and typing, is validated on 5000 simulated cubes built from actual SEDM observations of isolated host galaxies, covering a broad range of observing conditions and scene parameters. Results. We introduce the contrast, c, as the transient-to-total flux ratio at the SN location, integrated over the ZTF r-band. From estimated contrast distribution of real SEDm observations, we show that HyperGal correctly classifies ~95% of SNe Ia, and up to 99% for contrast c ≳ 0.2, representing more than 90% of the observations. Compared to the standard point-source extraction method (without the hyperspectral galaxy modeling step), HyperGal correctly classifies 20% more SNe Ia between 0.1 &lt; c &lt; 0.6 (50% of the observation conditions), with less than 5% of SN Ia misidentifications. The false-positive rate is less than 2% for c &gt; 0.1 (&gt; 99% of the observations), which represents half as much as the standard extraction method. Assuming a similar contrast distribution for core-collapse SNe, HyperGal classifies 14% additional SNe II and 11% additional SNe Ibc. Conclusions. HyperGal has proven to be extremely effective in extracting and classifying SNe in the presence of strong contamination by the host galaxy, providing a significant improvement with respect to the single point-source extraction.