Relative Spatial Configuration Research Articles

ПРОСТРАНСТВЕННЫЙ ФАКТОР В РАСПРЕДЕЛЕНИИ КОНФЛИКТОГЕННОСТИ НА ПОСТСОВЕТСКОЙ ТЕРРИТОРИИ (1992–2022 ГГ.)

Given that socio-political processes develop not only in time but also in space, their relative spatial configuration caninfluence their genesis and further evolution, which is manifested in the existence of neighborhood effect. Similar values of a phenomenon are clustered: the characteristics of the phenomenon in one location are determined not only by the qualities of this location itself but also by the characteristics of the same phenomenon in neighboring locations. The purpose of this study is to determine whetherneighborhood effect has influenced the spread of conflictogenicity in the post-Soviet space in 1992–2022 or, in other words, whetherconflictogenicity and its changes in this macroregion are clustered phenomena. The authors of this research define conflictogenicity asa cumulative indicator equal to the sum of conflictness scores of a unit of analysis (first-order administrative units of the former USSRrepublics) assigned to this unit from 1992 to 2022 by the Conflict Barometer project implemented by Heidelberg Institute for International Conflict Research. Conflictogenicity changes are defined as the difference between conflictogenicity scores assigned to administrative units in 1992–1999 and in 2000–2022. To achieve the purpose of the research, the authors use global and local Moran’s indicesof spatial and differential spatio-temporal autocorrelation. The results of the study demonstrate that during the given period in the postSoviet space both conflictogenicity and conflictogenicity changes are relatively clustered phenomena. The most robust autocorrelationrelationships are registered for administrative units with the highest conflict rates and regions where conflictogenicity changes turnedout to be very significant. Moreover, these two groups of territorial units are almost identical to each other: the greatest conflictogenicitychanges have been noted in local clusters with high conflictogenicity levels. Thus, during the post-bipolar period spatial patterns havebeen visible in the post-Soviet space both in the distribution and in the evolution of conflicts.

The Gas–Star Formation Cycle in Nearby Star-forming Galaxies. II. Resolved Distributions of CO and Hα Emission for 49 PHANGS Galaxies

Abstract The relative distribution of molecular gas and star formation in galaxies gives insight into the physical processes and timescales of the cycle between gas and stars. In this work, we track the relative spatial configuration of CO and Hα emission at high resolution in each of our galaxy targets and use these measurements to quantify the distributions of regions in different evolutionary stages of star formation: from molecular gas without star formation traced by Hα to star-forming gas, and to H ii regions. The large sample, drawn from the Physics at High Angular resolution in Nearby GalaxieS ALMA and narrowband Hα (PHANGS-ALMA and PHANGS-Hα) surveys, spans a wide range of stellar masses and morphological types, allowing us to investigate the dependencies of the gas‒star formation cycle on global galaxy properties. At a resolution of 150 pc, the incidence of regions in different stages shows a dependence on stellar mass and Hubble type of galaxies over the radial range probed. Massive and/or earlier-type galaxies in our sample exhibit a significant reservoir of molecular gas without star formation traced by Hα, while lower-mass galaxies harbor substantial H ii regions that may have dispersed their birth clouds or formed from low-mass, more isolated clouds. Galactic structures add a further layer of complexity to the relative distribution of CO and Hα emission. Trends between galaxy properties and distributions of gas traced by CO and Hα are visible only when the observed spatial scale is ≪500 pc, reflecting the critical resolution requirement to distinguish stages of the star formation process.

Tuning of relative spatial distributions of a two-component ion system to improve sympathetic cooling efficiency

Herein, a fine-tuning method is proposed for the spatial distributions of a mixed three-dimensional (3D) ion system in dual radio frequency (RF) linear Paul traps to achieve efficient sympathetic cooling. The dual RF field matching, efficient capture method and transient process of the intrinsic micromotion of the mixed ion system are analyzed quantitatively by numerical simulations. The 3D correlation coupling characteristics between intrinsic micromotion and secular motion of ion system are obtained. It is found that reasonable low-frequency trapping potential can produce ultra-low-frequency pulling effect on ions with low mass-to-charge ratio (M/Q), which is beneficial to the dynamic coupling between ions with large M/Q differences. The effects of equivalent stiffness coefficients [Formula: see text] on the relative spatial configuration and dynamic coupling process of mixed 3D ion crystals with large M/Q differences are discussed. By tuning [Formula: see text], radial distributions of laser-cooled ions (LCIs) and sympathetically cooled ions (SCIs) that do not conform to the rules based on M/Q are realized. The optimum sympathetic-cooling efficiency occurs, where [Formula: see text] is approximately equivalent to [Formula: see text]. These results are applicable to studies such as cold ion clocks, quantum logic manipulation, antimatter synthesis, regulation of cold chemical reaction, and precise spectral measurements based on sympathetic cooling.

СУЧАСНИЙ СТАН ТА ТЕНДЕНЦІЇ РОЗВИТКУ РАДІОЛОКАЦІЙНИХ СИСТЕМ АВІАЦІЙНО-НАЗЕМНОГО БАЗУВАННЯ ІЗ ЗМІННОЮ В ЧАСІ ВІДНОСНОЮ ПРОСТОРОВОЮ КОНФІГУРАЦІЄЮ

The work is devoted to the review of the current state and development trends of airborne-based radar systems with a time-varying relative spatial configuration. The relevance of consideration of the state and tendencies of development of radar systems of aviation-ground based with time-varying relative spatial configuration due to the practical need to obtain radar images (radars) of objects in the front area of the system review, taking into account the growing requirements for promptness and accuracy of image detection of real-time surveillance in a complex signal-interference environment. The generalized structure of the construction of the systems considered in the work is presented and the main prospects for their practical application in solving the problems of classifying radar objects and monitoring radio emission sources are determined. Estimates are given of the main qualitative characteristics of the images of radar objects when applied when using the systems considered and the accuracy of determining the coordinates of radio emission sources is estimated based on an approved mathematical apparatus. The priority areas of scientific research on the further development of the theory of multi-positional reception of radar information in the conditions of information uncertainty when using systems with a time-variable relative spatial configuration are determined.

Viewing Direction Estimation in Cryo-EM Using Synchronization

A central task in recovering the structure of a macromolecule from cryo-electron microscopy (cryo-EM) images is to determine a three-dimensional model of the macromolecule given many of its two-dimensional projection images. The direction from each image taken the images which was is unknown, and are small and extremely noisy. The goal is to determine the direction from which each image was taken and then to combine the images into a three-dimensional model of the molecule. We present an algorithm for determining the viewing direction of all cryo-EM images at once, which is robust to high levels of noise. The algorithm is based on formulating the problem as a synchronization problem; that is, we estimate the relative spatial configuration of pairs of images and then estimate a global assignment of orientations that maximizes the number of satisfied pairwise relations. Information about the spatial relation between pairs of images is extracted from common lines between triplets of images. These noisy pairwise relations are combined into a single consistent assignment of orientations by constructing a matrix whose entries encode the pairwise relations. This matrix is shown to have rank 3, and its nontrivial eigenspace is shown to reveal the projection orientation of each image. In particular, we show that the nontrivial eigenvectors encode the rotation matrix that corresponds to each image.

The Three-Dimensional Organization of Polyribosomes in Intact Human Cells

Structural studies have provided detailed insights into different functional states of the ribosome and its interaction with factors involved in nascent peptide folding, processing, and targeting. However, how the translational machinery is organized spatially in native cellular environments is not yet well understood. Here we have mapped individual ribosomes in electron tomograms of intact human cells by template matching and determined the average structure of the ribosome in situ. Characteristic features of active ribosomes in the cellular environment were assigned to the tRNA channel, elongation factors, and additional densities near the peptide tunnel. Importantly, the relative spatial configuration of neighboring ribosomes in the cell is clearly nonrandom. The preferred configurations are specific for active polysomes and were largely abrogated in puromycin-treated control cells. The distinct neighbor orientations found in situ resemble configurations of bacterial polysomes in vitro, indicating a conserved supramolecular organization with implications for nascent polypeptide folding.

Robust iris indexing scheme using geometric hashing of SIFT keypoints

This paper proposes an efficient indexing scheme for searching large iris biometric database that achieves invariance to similarity transformations, illumination and occlusion. The proposed scheme considers local descriptors as well as relative spatial configuration for claiming identity. To overcome the effect of non-uniform illumination and partial occlusion due to eyelids, local features are extracted from noise independent annular iris image using scale invariant feature transform (SIFT). The detected keypoints are used to index iris database by applying geometric hashing scheme that is robust to similarity transformations as well as occlusion. During iris retrieval, geometric hashed location from query iris image is obtained to access the appropriate bin of hash table and for every entry found there, a vote is casted. The iris images that receive more than certain number of votes are considered as possible candidates. In order to find the potential matches, the keypoint descriptor of the list of possible candidates is matched with the query iris. Since only small portion of database is scanned to find a match it reduces the query retrieval time and improves accuracy. This approach is tested on UBIRIS, BATH, CASIA and IITK iris databases and shows a substantial improvement over exhaustive search technique in terms of time and accuracy.

Differential Response Patterns in the SI Barrel and Septal Compartments During Mechanical Whisker Stimulation

A growing body of evidence suggests that the barrel and septal regions in layer IV of rat primary somatosensory (SI) cortex may represent separate processing channels. To assess this view, pairs of barrel and septal neurons were recorded simultaneously in the anesthetized rat while a 4x4 array of 16 whiskers was mechanically stimulated at 4, 8, 12, and 16 Hz. Compared with barrel neurons, regular-spiking septal neurons displayed greater increases in response latencies as the frequency of whisker stimulation increased. Cross-correlation analysis indicated that the incidence and strength of neuronal coordination varied with the relative spatial configuration (within vs. across rows) and compartmental location (barrel vs. septa) of the recorded neurons. Barrel and septal neurons were strongly coordinated if both neurons were in close proximity and resided in the same row. Some barrel neurons were weakly coordinated, but only if they resided in the same row. By contrast, the strength of coordination among pairs of septal neurons did not vary with their spatial proximity or their spatial configuration within the arcs and rows of the barrel field. These differential responses provide further support for the view that the barrel and septal regions represent the cortical gateway for processing streams that encode specific aspects of the sensorimotor information associated with whisking behavior.

Effect of Absolute Configuration on the Formation of TGBA* Phase in Liquid Crystallines Containing Two Stereogenic Centres

Our previous work has shown that a homologous series of chiral materials containing two sereogenic centres, (R)-2-pentyl (S)-2-(6-(4-(4-alkoxyphenyl)benzoyloxy-2-naphthyl)propionates (R,S)PmPBNP (m=7−14). exhibited TGBA* phase. To understand the effect of relative configuration of two stereogenic centres at chiral tail on the appearance of TGBA* phase, two stereoisomers of (R,S)P11PBNP, (S,S)P11PBNP and (±,S)P11PBNP were synthesized and their mesophases investigated. The results showed that both isomers also possessed TGBA* phase with the phase sequence of I-N*-TGBA*-SA*-Sc*-C, The temperature range of TGBA* phase in (R,S)-isomer was significantly larger than that in (S,S)-isomer, indicating the stability of TGBA* phase was affected by the relative spatial configuration of the second chiral centre at chiral tail. In addition, the temperature range of TGBA* phase in (±,S)-isomer was larger than (S,S)-isomer, suggesting that an introducing methyl branched group at the external side of mono chiral centre could cause a weakening of smectic layer order and result in an occurrence of TGBA* phase. The measured Ps values in the Sc* phase from the isomers, also indicated the absolute configuration of second chiral centre plays an important role in determining the magnitude of spontaneous polarization.

Generalized mean spherical approximations.

A criterion for determining the coupling and the exponent [K(\ensuremath{\eta},\ensuremath{\beta}) and \ensuremath{\zeta}(\ensuremath{\eta},\ensuremath{\beta})] of the one-Yukawa generalized mean spherical approximation (GMSA), which better describes a given real fluid, is suggested. The relative spatial configuration of the surface (\ensuremath{\equiv}${\ensuremath{\Sigma}}_{\ensuremath{\chi}}$) where the compressibility diverges, with respect to the surface (\ensuremath{\equiv}${\ensuremath{\Sigma}}_{\ensuremath{\Delta}}$) bounding the region where physical solutions of the GMSA equations exist, is studied in terms of K, \ensuremath{\zeta}, and \ensuremath{\eta} (the packing fraction). ${\ensuremath{\Sigma}}_{\ensuremath{\chi}}$ is found to lie always in the physically accessible region and to become tangent to ${\ensuremath{\Sigma}}_{\ensuremath{\Delta}}$ along the \ensuremath{\eta} axis; that consequently will be the locus of the critical points of the real systems. By the aforesaid criterion we show that the Baxter solution of the adhesive hard-sphere model can be obtained from the limit of the GMSA solution as \ensuremath{\zeta}\ensuremath{\rightarrow}\ensuremath{\infty}. The study of the limit \ensuremath{\zeta}\ensuremath{\rightarrow}0 shows that the GMSA critical indices are generally different from the mean-field ones and that their values depend on the way \ensuremath{\zeta} approaches zero as one moves along the critical isochore and the critical isotherm. Attention is also called to the fact that, as \ensuremath{\zeta}\ensuremath{\rightarrow}0, K(\ensuremath{\eta},\ensuremath{\zeta})/${\ensuremath{\zeta}}^{2}$ has a minimum at \ensuremath{\eta}=0.128, a value rather close to the critical densities of the real fluids.