Space Resolution Research Articles

3D spatial resolution characterization for volumetric computed tomography

Spatial resolution is a key parameter that determines the smallest resolved scale in volumetric computed tomography. However, the evaluation process is typically confined within a plane, and tomographic resolution is usually treated as a two dimensional concept. In this work, the full map of three-dimensional (3D) spatial resolution along radial directions was obtained through combined volumetric laser induced fluorescence measurement on a well-controlled test rig, tomographic reconstruction, and successive resolution analysis. The results show non-uniformly distributed spatial resolution and weak dependence on view angles. Moreover, both experimental and algorithmic factors on spatial resolution were quantitatively quantified. The convergence of the spatial resolution was then validated through a series of computation with increasing voxel numbers. It is found that the spatial resolution improves until the number of voxels reaches ∼19.6 times as much the value set by the linear algebraic limit. The ultimate spatial resolution that can be obtained with our setup is about 1.35 lp/mm, which is twice the value of a well-posed system. The results show that the method of this work is more appropriate to quantify spatial resolution in 3D space. The conclusions made in this work can be generalized for applications with other tomography-based measurements.

A kiloelectron-volt ultrafast electron micro-diffraction apparatus using low emittance semiconductor photocathodes.

We report the design and performance of a time-resolved electron diffraction apparatus capable of producing intense bunches with simultaneously single digit micrometer probe size, long coherence length, and 200 fs rms time resolution. We measure the 5d (peak) beam brightness at the sample location in micro-diffraction mode to be . To generate high brightness electron bunches, the system employs high efficiency, low emittance semiconductor photocathodes driven with a wavelength near the photoemission threshold at a repetition rate up to 250 kHz. We characterize spatial, temporal, and reciprocal space resolution of the apparatus. We perform proof-of-principle measurements of ultrafast heating in single crystal Au samples and compare experimental results with simulations that account for the effects of multiple scattering.

Interaction of human erythrocyte catalase with air-water interface in cryoEM.

One of the key goals in single-particle cryo-microscopy is to obtain a uniform distribution of particle orientations, so that the three-dimensional structure has isotropic resolution in Fourier space. A common problem arises from the interaction of protein molecules with the air–water interface that exists on both surfaces of the thin film of liquid that is formed prior to plunge-freezing into liquid ethane. Some proteins and other macromolecular complexes are disrupted by interaction with the air–water interface. Other proteins or macromolecules either become concentrated through their interaction with the interface or are excluded because they bind strongly to some other part of the grid or the filter paper used in blotting. In this paper, the interaction of human erythrocyte catalase with the air–water interface is investigated and minimized by the addition of certain detergents. Detergents can form an amphipathic monolayer at the air–water interface that creates a barrier and leaves the molecules free to adopt a variety of orientations, thus facilitating the 3D structure determination. These results suggest that further characterization and development of detergents for cryo-microscopy plunge-freezing would be useful.

New Horizons in Structural Biology of Membrane Proteins: Experimental Evaluation of the Role of Conformational Dynamics and Intrinsic Flexibility.

A plethora of membrane proteins are found along the cell surface and on the convoluted labyrinth of membranes surrounding organelles. Since the advent of various structural biology techniques, a sub-population of these proteins has become accessible to investigation at near-atomic resolutions. The predominant bona fide methods for structure solution, X-ray crystallography and cryo-EM, provide high resolution in three-dimensional space at the cost of neglecting protein motions through time. Though structures provide various rigid snapshots, only an amorphous mechanistic understanding can be inferred from interpolations between these different static states. In this review, we discuss various techniques that have been utilized in observing dynamic conformational intermediaries that remain elusive from rigid structures. More specifically we discuss the application of structural techniques such as NMR, cryo-EM and X-ray crystallography in studying protein dynamics along with complementation by conformational trapping by specific binders such as antibodies. We finally showcase the strength of various biophysical techniques including FRET, EPR and computational approaches using a multitude of succinct examples from GPCRs, transporters and ion channels.

Development of a retention prediction model in ion-pair reversed-phase HPLC for nucleoside triphosphates used as mRNA vaccine raw materials

The International Conference on Harmonization guidelines for quality on pharmaceutical development recommends a systematic development approach including robustness studies which assure performance of manufacturing and analytical method development of drug product. It was demonstrated that the retention prediction model for nucleoside triphosphates (NTPs) on ion-pair reversed-phase HPLC was developed by a highly accurate Kawabe’s model which supports the development of robust HPLC methods. As NTPs and its derivatives are typically used for Messenger ribonucleic acid (mRNA) vaccine production, adenosine-5′-triphosphate (ATP), guanosine-5′-triphosphate (GTP), cytidine-5′-triphosphate (CTP), 5-methylcytidine-5′-triphosphate (m5-CTP), uridine-5′-triphosphate (UTP), 5-methyluridine-5′-triphosphate (m5-UTP), pseudouridine-5′-triphosphate (Ψ-UTP) and N1-methylpseudouridine-5′-triphosphate (m1Ψ-UTP) were applied for prediction model development. By a comparison of the predicted retention factor in eight studied samples with the retention factor measured under six isocratic conditions, the absolute prediction error was 0.075 and also the prediction error (%) was 2.70%. In practical examples, analytical method for residual ATP, GTP, CTP, and m1Ψ-UTP in the commercial mRNA-based drugs and purity method for UTP derivatives were optimized by QbD approach. The design space for the minimum resolution between adjacent peaks was simulated with the models developed to evaluate the robustness of peak separation, and the optimal mobile phase condition was also simulated. As a conclusion, the desired peak was successfully separated under the optimized condition, and we thought that these retention models could optimize the mobile phase condition of the NTP analysis method for applying to various quality tests, such as quantity, purity and identity test for NTPs and its derivates in the mRNA-based drugs.

Room-Temperature Molecular Manipulation via Plasmonic Trapping at Electrified Interfaces.

For the motion control of individual molecules at room temperature, optical tweezers could be one of the best approaches to realize desirable selectivity with high resolution in time and space. Because of physical limitations due to the thermal fluctuation, optical manipulation of small molecules at room temperature is still a challenging subject. The difficulty of the manipulation also emerged from the variation of molecular polarizability depending on the choice of molecules as well as the molecular orientation to the optical field. In this article, we have demonstrated plasmonic optical trapping of small size molecules with less than 1 nm at the gap of a single metal nanodimer immersed in an electrolyte solution. In situ electrochemical surface-enhanced Raman scattering measurements prove that a plasmonic structure under electrochemical potential control realizes not only the selective molecular condensation but also the formation of unique mixed molecular phases which is distinct from those under a thermodynamic equilibrium. Through detailed analyses of optical trapping behavior, we established the methodology of plasmonic optical trapping to create the novel adsorption isotherm under applying an optical force at electrified interfaces.

THE URGENCY OF CULTURAL REVITALIZATION IN THE INDONESIA-MALAYSIA BORDER REGION

This study focuses on the cultural revitalization aspect as an urgent matter in the Indonesia-Malaysia border region, SajinganBesar Sub-district, Sambas Regency. The results of this study can be summarized that the main problem of cultural development in the border region is not only caused by globalization but also concerns on the condition of cultural resilience of the border communities themselves who have experienced stagnation which is from the conditions that are completely and inevitably marginal of Globalization, then it must be anticipated with cultural development that is characterized by the reinforcement of identity and local wisdom of the border community which is used as the basis for arranging strategies in preserving and developing culture. This study used a qualitative approach that was carried out by survey data, observation, analysis and FGD (Forum Group Discussion). This method is very effective for something that is urgent and important and will provide an increase in the welfare of the community whose life is generally less prosperous. Moreover, geopolitically, the cultural revitalization will further ensure the realization of the revitalization policy of the culture of the Indonesian Archipelago in the border region which can create nationalism, and maintain the border region from foreign infiltration as well as become a space for conflict resolution to create peace between countries.
 This study focuses on the cultural revitalization aspect as an urgent matter in the Indonesia-Malaysia border region, Sajingan Besar Sub-district, Sambas Regency. The results of this study can be summarized that the main problem of cultural development in the border region is not only caused by globalization but also concerns on the condition of cultural resilience of the border communities themselves who have experienced stagnation which is from the conditions that are completely and inevitably marginal of Globalization, then it must be anticipated with cultural development that is characterized by the reinforcement of identity and local wisdom of the border community which is used as the basis for arranging strategies in preserving and developing culture. This study used a qualitative approach that was carried out by survey data, observation, analysis and FGD (Forum Group Discussion). This method is very effective for something that is urgent and important and will provide an increase in the welfare of the community whose life is generally less prosperous. Moreover, geopolitically, the cultural revitalization will further ensure the realization of the revitalization policy of the culture of the Indonesian Archipelago in the border region which can create nationalism, and maintain the border region from foreign infiltration as well as become a space for conflict resolution to create peace between countries.

Diffusion of a disordered protein on its folded ligand

Flexibility in complexes between intrinsically disordered proteins and folded ligands is widespread in nature. However, timescales and spatial amplitudes of such dynamics remained unexplored for most systems. Here, we directly measure the dynamics in an exceptionally mobile, high-affinity complex. We show that the disordered tail of the cell adhesion protein E-cadherin dynamically samples a large surface area of the protooncogene β-catenin. Single-molecule experiments and molecular simulations resolve these motions with high resolution in space and time.

Fine-Scale Velocity Measurement on the Wirewalker Wave-Powered Profiler

Abstract The Wirewalker (WW) ocean-wave-powered vertical profiling system allows the collection of high-resolution oceanographic data due to its rapid profiling, hydrodynamically quiet operation, and long endurance. We have assessed the potential for measuring fine-scale ocean velocities from the Wirewalker platform using commercially available acoustic velocimeters. Although the vertical profiling speed is relatively steady, platform motion affects the velocity measurements and requires correction. We present an algorithm to correct our velocity estimates using platform motion calculated from the inertial sensors—accelerometer, gyroscope, and magnetometer—on a Nortek Signature1000 acoustic Doppler current profiler (ADCP). This correction, carried out ping by ping, was effective in removing the vehicle motion from the measured velocities. The motion-corrected velocities contain contributions from surface wave orbital velocities, especially near the surface, and the background currents. To proceed, we use an averaging approach that leverages both the vertical platform profiling of the system and the ∼15–20 m vertical profiling range resolution of the down-looking ADCP to separate the surface wave orbital velocities and the background flow. The former can provide information on the wave conditions. From the latter, we are able to estimate fine-scale velocity and shear with spectral wavenumber rolloff at vertical scales around 3 m, a vertical resolution several times finer than that possible from modern shipboard or fixed ADCPs with similar profiling range, and similar to recent glider measurements. When combined with a continuous time series of buoy drift calculated from the onboard GPS, a highly resolved total velocity field is obtained, with a unique combination of space and time resolution.

An Energy Conserving Vlasov Solver That Tolerates Coarse Velocity Space Resolutions: Simulation of MMS Reconnection Events

AbstractVlasov solvers that operate on a phase‐space grid are highly accurate but also numerically demanding. Coarse velocity space resolutions, which are largely unproblematic in particle‐in‐cell (PIC) simulations, can lead to numerical heating or oscillations in continuum Vlasov methods. To address this issue, we present a new dual Vlasov solver which is based on an established positivity preserving advection scheme for the update of the distribution function and an energy conserving partial differential equation solver for the kinetic update of mean velocity and temperature. The solvers work together via moment fitting during which the maximum entropy part of the distribution function is replaced by the solution from the partial differential equation solver. This numerical scheme makes continuum Vlasov methods competitive with PIC methods concerning computational cost and enables us to model large scale reconnection in Earth's magnetosphere with a fully kinetic continuum method. The simulation results agree well with measurements by the MMS spacecraft.

Experimental and Data Analysis Workflow for Soft Matter Nanoindentation.

Nanoindentation refers to a class of experimental techniques where a micrometric force probe is used to quantify the local mechanical properties of soft biomaterials and cells. This approach has gained a central role in the fields of mechanobiology, biomaterials designand tissue engineering, to obtain a proper mechanical characterization of soft materials with a resolution comparable to the size of single cells (μm). The most popular strategy to acquire such experimental data is to employ an atomic force microscope (AFM); while this instrument offers an unprecedented resolution in force (down to pN) and space (sub-nm), its usability is often limited by its complexity that prevents routine measurements of integral indicators of mechanical properties, such as Young's Modulus (E). A new generation of nanoindenters, such as those based on optical fiber sensing technology, has recently gained popularity for its ease of integration while allowing to apply sub-nN forces with µm spatial resolution, therefore being suitable to probe local mechanical properties of hydrogels and cells. In this protocol, a step-by-step guide detailing the experimental procedure to acquire nanoindentation data on hydrogels and cells using a commercially available ferrule-top optical fiber sensing nanoindenter is presented. Whereas some steps are specific to the instrument used herein, the proposed protocol can be taken as a guide for other nanoindentation devices, granted some steps are adapted according to the manufacturer's guidelines. Further, a new open-source Python software equipped with a user-friendly graphical user interface for the analysis of nanoindentation data is presented, which allows for screening of incorrectly acquired curves, data filtering, computation of the contact point through different numerical procedures, the conventional computation of E, as well as a more advanced analysis particularly suited for single-cell nanoindentation data.

Climate Change Impacts on Polar Marine Ecosystems: Toward Robust Approaches for Managing Risks and Uncertainties

The Polar Regions chapter of the Intergovernmental Panel on Climate Change's Special Report on the Ocean and Cryosphere in a Changing Climate (SROCC) provides a comprehensive assessment of climate change impacts on polar marine ecosystems and associated consequences for humans. It also includes identification of confidence for major findings based on agreement across studies and weight of evidence. Sources of uncertainty, from the extent of available datasets, to resolution of projection models, to the complexity and understanding of underlying social-ecological linkages and dynamics, can influence confidence. Here we, marine ecosystem scientists all having experience as lead authors of IPCC reports, examine the evolution of confidence in observed and projected climate-linked changes in polar ecosystems since SROCC. Further synthesis of literature on polar marine ecosystems has been undertaken, especially within IPCC's Sixth Assessment Report (AR6) Working Group II; for the Southern Ocean also the Marine Ecosystem Assessment for the Southern Ocean (MEASO). These publications incorporate new scientific findings that address some of the knowledge gaps identified in SROCC. While knowledge gaps have been narrowed, we still find that polar region assessments reflect pronounced geographical skewness in knowledge regarding the responses of marine life to changing climate and associated literature. There is also an imbalance in scientific focus; especially research in Antarctica is dominated by physical oceanography and cryosphere science with highly fragmented approaches and only short-term funding to ecology. There are clear indications that the scientific community has made substantial progress in its ability to project ecosystem responses to future climate change through the development of coupled biophysical models of the region facilitated by increased computer power allowing for improved resolution in space and time. Lastly, we point forward—providing recommendations for future advances for IPCC assessments.

Predicting Spatio-Temporal Human Brain Response Using fMRI.

The transformation and transmission of brain stimuli reflect the dynamical brain activity in space and time. Compared with functional magnetic resonance imaging (fMRI), magneto- or electroencephalography (M/EEG) fast couples to the neural activity through generated magnetic fields. However, the MEG signal is inhomogeneous throughout the whole brain, which is affected by the signal-to-noise ratio, the sensors' location and distance. Current non-invasive neuroimaging modalities such as fMRI and M/EEG excel high resolution in space or time but not in both. To solve the main limitations of current technique for brain activity recording, we propose a novel recurrent memory optimization approach to predict the internal behavioral states in space and time. The proposed method uses Optimal Polynomial Projections to capture the long temporal history with robust online compression. The training process takes the pairs of fMRI and MEG data as inputs and predicts the recurrent brain states through the Siamese network. In the testing process, the framework only uses fMRI data to generate the corresponding neural response in space and time. The experimental results with Human connectome project (HCP) show that the predicted signal could reflect the neural activity with high spatial resolution as fMRI and high temporal resolution as MEG signal. The experimental results demonstrate for the first time that the proposed method is able to predict the brain response in both milliseconds and millimeters using only fMRI signal.

Baltic Sea transparency from ships and satellites: centennial trends

Water transparency can be measured with optical instruments and estimated with satellite sensors, but such measurements have been widely available for only a few decades. Estimates of water transparency using a white disk called a Secchi disk have been made for over a century and can be used to estimate long-term trends. However, historic in situ measurements of the Secchi depth (ZSd) were irregular in space and time and are difficult to interpret in regular time series due to biases introduced by changing locations and the timing of measurements. Satellite data time series, on the other hand, have consistent resolution in both space and time but cover too short a time to resolve climate-scale trends. We normalized historic ZSd measurements in the Baltic Sea with a satellite-derived mean climatology at 5 d temporal and 4 km spatial resolutions and created a merged time series of ZSd for the last century. The mean ZSd in the Baltic Sea from 1927-2020 decreased by 4.2 ± 0.6 m at a rate of 0.045 ± 0.06 m yr-1. Most of the change happened before 1987, and a further decrease was evident primarily in the satellite data during the 1998-2008 period. After 2008, no significant trend in ZSd and or the coefficient of diffuse light attenuation was detected in the Baltic Sea. However, in some sub-basins of the Baltic Sea, the decrease in ZSd continued even after that. The decrease in spectral water transparency in recent decades was highest in the 412 nm band, indicating an increase in the concentration of chromophoric dissolved organic matter.

Pandemonium: a clustering tool to partition parameter space\u2014application to the B anomalies

We introduce the interactive tool pandemonium to cluster model predictions that depend on a set of parameters. The model predictions are used to define the coordinates in observable space which go into the clustering. The results of this partitioning are then visualized in both observable and parameter space to study correlations between them. The tool offers multiple choices for coordinates, distance functions and linkage methods within hierarchical clustering. It provides a set of diagnostic statistics and visualization methods to study the clustering results in order to interpret the outcome. The methods are most useful in an interactive environment that enables exploration, and we have implemented them with a graphical user interface in R. We demonstrate the concepts with an application to phenomenological studies in flavor physics in the context of the so-called B anomalies, exploring the tension between P_5^prime and R_K and quantifying the resolution in parameter space that can be provided by a given observable set.

Quasi judicial institutions in the civilization space for labor dispute resolution

This article examines conciliatory forms of proceedings for complaints and disputes related to the application of labor legislation or conditions of certain contracts that echo the past and modern period of extrajudicial forms; it also emphasizes that the period of the new economic policy was due to the phenomenon of rationalization and individualization of consciousness. The normative base of the conciliation and intermediary institutions of the early Soviet period is analyzed, and the competence of the assessment and conflict commissions is shown. The first norms of labor legislation emphasized democracy and attention to the literal mathematical equality of the parties during procedures for resolving conflicts and resolving cases, which has reference to the classical judicial principles of openness, publicity, transparency, and parity in proceedings, and allows us to make a reservation in terms of confusion and inconsistency and rationing the activities of all quasi-judicial institutions. Conciliation and mediation institutions, on the one hand, were built into the system of labor relations, and on the other hand, they are qualified as quasi-judicial, with all the signs of judicial activity. The relevance of the study lies in the fact that conciliatory activity in the civilizational space has been poorly studied, and in this regard, the study has historical significance, and has parallels with the practice of modern labor dispute commissions, conciliation commission, mediator, labor arbitration, arbitration court, mediator, lawyer, notary, and other conciliatory and intermediary institutions. Also, the parallels of the past years against the background of the reconstruction of archival materials and files according to the reports of the craft department of the workshop against the background of the industrial panorama of Belarusian cities in the 19th — early 20th centuries, the industrial appearance of the city of Minsk.

Observation of photo-excited carrier dynamics in semiconductors with time, space, and energy resolutions

Observation of photo-excited carrier dynamics in semiconductors with time, space, and energy resolutions

ЧИСЛЕННАЯ МОДЕЛЬ ОГНЕНЕПРОНИЦАЕМОСТИ ЭЛЕМЕНТОВ ГАЗОТУРБИННЫХ ДВИГАТЕЛЕЙ ИЗ АЛЮМИНИЕВЫХ СПЛАВОВ

For the early stages of design, a numerical model of fire resistance and fire permeability of GTE elements made of alu-minum alloys is proposed. The numerical model is based on the solution of three-dimensional Navier-Stokes equations, closed by a two-parameter isotropic SST – turbulence model. We used an implicit pressure solver and a scheme of second-order accuracy in High Resolution space, which allows lowering the approximation order to the first in the areas of solution discontinuities and high gradients to increase the monotonicity and stability of the solution. Additionally, to achieve the solution stability, the High Speed Numerics solver option was used, activating the solver settings Gradient Factor Relaxation = 0.1 and Blend Factor Relaxation = 0.1. The mathematical model for the thermal-hydraulic calculation was set up in the formulation of the coupled heat transfer, taking into account radiation based on the discrete transfer model of the Participating Media. The influ-ence of the degree of blackness on the results of the numerical model is investigated and the most rational radiation model is chosen. The numerical model was validated according to the results of engineering tests on the fire permeability of the plate not cooled by the air flow using a kerosene burner NexGen of the bench Ts17-G3 of FAU P.I. Baranov TsIAM. The obtained results of calculations on fire permeability are comparable with the experimental data both quantitatively and qualitatively. The developed un-steady numerical model of fire permeability of flat plates of aluminum alloys under conditions of free convection can be used in the de-sign of the fan housing by selecting the most rational structural and layout solutions, such as the thickness of the housing, the presence of fire protection coating, cooling intensity, etc.

ЗАКОНОМЕРНОСТИ СОВРЕМЕННОГО ИСПОЛЬЗОВАНИЯ ЗАБРОШЕННЫХ СЕЛЬСКОХОЗЯЙСТВЕННЫХ ЗЕМЕЛЬ В ШИРОКОЛИСТВЕННО-ЛЕСНОЙ И ЛЕСОСТЕПНОЙ ЗОНАХ РЕСПУБЛИКИ БАШКОРТОСТАН

We analyzed modern use of arable lands of 1985 before the collapse of collective and state farms using high resolution space imagery and grid mapping. Two model sites of 10×10 km were used, with the first one located at the northern border of broad-leaved forests of the Bashkortostan Republic ("Mishkinsky"), and the second one located in the forest-steppe ("Belebeyevsky"). In 1985 the area of arable land at the "Mishkinskiy" site was 60% higher than the "Belebeyevskiy" site due to the difference in the slope steepness. Presently, the area of arable land in the "Mishkinsky" and "Belebeyevsky" sites decreased by 72% and 64% respectively. Forest overgrowth covers a little more than half of the initial arable land in both sites. "Mishkinsky" forest stands are dominated by Betula pendula, with Pinus sylvestris dominating the "Belebeyevsky" forests. Abandoned fallows are more often used as hayfields and pastures at the "Mishkinsky" site, while grass vegetation overgrowth share is higher at the "Belebeyevsky" site. In addition, woody vegetation is being cleared at the "Belebeyevsky" site to reuse the land. Young fast-growing forest overgrowth is of great interest as wood source and as a part of carbon farms to achieve carbon neutrality of the Bashkortostan Republic.

Brightness Compensation for GF-3 SAR Images Based on Cycle-Consistent Adversarial Networks

GF-3 is the first C-Band full-polarimetric synthetic aperture radar (SAR) satellite with a space resolution up to 1m in China. The uneven brightness of SAR images is a problem when using GF-3 images, which makes it difficult to use and produce SAR images. In this paper, a brightness compensation method is proposed for GF-3 SAR images with unbalanced brightness in some areas based on a deep learning model named Cycle-Consistent Adversarial Networks (CycleGAN). The proposed method makes the image brightness relatively consistent, and it is compared with the MASK dodging algorithm, Wallis dodging algorithm and histogram equalization in terms of the profiles, brightness mean, standard deviation, and average gradient. Results of brightness compensation show that, the proposed method makes the inner brightness differences smaller, and the image quality is obviously improved, which provides even brightness image for subsequent applications, and has great practical significance.