Opposite Orientation Research Articles

Saccades and presaccadic stimulus repetition alter cortical network topology and dynamics: evidence from EEG and graph theoretical analysis.

Parietal and frontal cortex are involved in saccade generation, and their output signals modify visual signals throughout cortex. Local signals associated with these interactions are well described, but their large-scale progression and network dynamics are unknown. Here, we combined source localized electroencephalography (EEG) and graph theory analysis (GTA) to understand how saccades and presaccadic visual stimuli interactively alter cortical network dynamics in humans. Twenty-one participants viewed 1-3 vertical/horizontal grids, followed by grid with the opposite orientation just before a horizontal saccade or continued fixation. EEG signals from the presaccadic interval (or equivalent fixation period) were used for analysis. Source localization-through-time revealed a rapid frontoparietal progression of presaccadic motor signals and stimulus-motor interactions, with additional band-specific modulations in several frontoparietal regions. GTA analysis revealed a saccade-specific functional network with major hubs in inferior parietal cortex (alpha) and the frontal eye fields (beta), and major saccade-repetition interactions in left prefrontal (theta) and supramarginal gyrus (gamma). This network showed enhanced segregation, integration, synchronization, and complexity (compared with fixation), whereas stimulus repetition interactions reduced synchronization and complexity. These cortical results demonstrate a widespread influence of saccades on both regional and network dynamics, likely responsible for both the motor and perceptual aspects of saccades.

A Novel Mutator-Like Transposable Elements With Unusual Structure and Recent Transpositions in Barley (Hordeum vulgare).

Mutator-like transposable elements (MULEs) represent a unique superfamily of DNA transposons as they can capture host genes and cause higher frequency of mutations in some eukaryotes. Despite their essential roles in plant evolution and functional genomics, MULEs are not fully understood yet in many important crops including barley (Hordeum vulgare). In this study, we analyzed the barley genome and identified a new mutator transposon Hvu_Abermu. This transposon is present at extremely high copy number in barley and shows unusual structure as it contains three open reading frames (ORFs) including one ORF (ORF1) encoding mutator transposase protein and one ORF (ORFR) showing opposite transcriptional orientation. We identified homologous sequences of Hvu_Abermu in both monocots and dicots and grouped them into a large mutator family named Abermu. Abermu transposons from different species share significant sequence identity, but they exhibit distinct sequence structures. Unlike the transposase proteins which are highly conserved between Abermu transposons from different organisms, the ORFR-encoded proteins are quite different from distant species. Phylogenetic analysis indicated that Abermu transposons shared closer evolutionary relationships with the maize MuDR transposon than other reported MULEs. We also found phylogenetic incongruence for the Abermu transposons identified in rice and its wild species implying the possibility of horizontal transfer of transposon. Further comparison indicated that over 200 barley genes contain Abermu-related sequences. We analyzed the barley pan genomes and detected polymorphic Hvu_Abermu transposons between the sequenced 23 wild and cultivated barley genomes. Our efforts identified a novel mutator transposon and revealed its recent transposition activity, which may help to develop genetic tools for barley and other crops.

Half-topological state in magnetic topological insulators

We predict a novel topological state, half-topological state, in magnetic topological insulators. The topological state is characterized by different topologies of electrons with different spin orientations, i.e., electrons with one spin orientation occupy a nontrivial topological insulating state, while electrons with opposite orientation occupy another insulating state with trivial topology. We demonstrate the occurrence of the half-topological state in magnetic topological insulators by employing a minimal model. The minimal model is a combination of the spinful Haldane and the double-exchange models. The double-exchange processes maintain a spontaneous magnetic ordering, while the next-nearest-neighbor hopping in the Haldane model gives rise to a nontrivial topological insulator. The minimal model is studied by applying the dynamical mean field theory. It is found that the long-range antiferromagnetic ordering drives the system from either topological or topologically trivial antiferromagnetic insulator to the half-topological state, and finally to topologically trivial antiferromagnetic insulator. The equations for the topological phase transitions are also explicitly derived.

Alternating odd pretzel knots and chirally cosmetic surgeries

A pair of surgeries on a knot is chirally cosmetic if they result in homeomorphic manifolds with opposite orientations. Using recent methods of Ichihara, Ito, and Saito, we show that, except for the (2, 5) and (2, 7)-torus knots, the genus 2 and 3 alternating odd pretzel knots do not admit any chirally cosmetic surgeries. Further, we show that for a fixed genus, at most finitely many alternating odd pretzel knots admit chirally cosmetic surgeries.

Combined film and impingement cooling of flat plate with reverse cooling hole

• Performance of combined impingement-film cooling is analyzed for a flat plate. • Effectiveness and pressure drop are compared for forward and reverse injections. • Effectiveness is found to be lower for the reverse injection at lower blowing ratio. • Contrary effect of cooling hole orientation is noticed at higher blowing ratio. • Pressure drop is also lower in case of the reverse orientation of the cooling hole. A numerical model is developed in the present work for analysing cooling performance of combined impingement-film cooling under realistic engine operating conditions. Effect of jet impingement along with the film cooling is analysed on fluid flow, heat transfer, cooling performance and pressure drop for forward and reverse orientations of the cooling hole. Further, effect of hole orientation on the cooling performance is studied under wide range of blowing ratios and jet-to-plate spacings. It is observed that the effect of jet impingement is significant on the cooling performance. Surface temperature of the metallic plate is found to be 50–90 °C lower for the combined jet impingement and film cooling case as compared to the only film cooling case. The improvement in the heat transfer for combined impingement-film cooling is at the cost of increased pressure drop. Film cooling effectiveness for the case of combined impingement-film cooling is found to be dependent on the hole orientation and blowing ratio. The secondary jet penetration into the mainstream increases with increase in the blowing ratio/velocity ratio. Kidney-vortices are formed at a velocity ratio of 1.07 from forward injection which resulted in decreased film cooling effectiveness. These kidney-vortices were not formed for the case of reverse injection and coolant spreads uniformly in the transverse direction. At lower velocity ratios when formation of kidney vortices is not prominent, forward injection results in better film cooling effectiveness compared to the reverse injection. Gas radiation is also considered in the modelling and its effect is found significant on the temperature prediction of the components.

Do Red-cockaded Woodpecker (Dryobates borealis) cavity locations provide olfactory concealment from predators?

Nest site selection is crucial for survival and fecundity of birds. Predators find nests using visual, aural, thermal, and olfactory cues, yet few studies have evaluated olfactory concealment of nests. Rat snakes (Pantherophis spp.) are common nest predators that use ground-level olfactory cues to detect nest locations. In Arkansas, USA, we evaluated if cavity locations of the Red-cockaded Woodpecker (Dryobates borealis, RCW), a species that experiences nest predation by rat snakes, were associated with airflow conditions known to provide olfactory concealment for other bird species. We used a 3-dimensional sonic anemometer to measure ground-level air velocity, turbulence, and turbulence intensity at cavity trees and unused trees, and at cavity and opposite orientations on trees. For all airflow variables, we found no differences between used and unused trees and orientations. Other factors such as landscape-scale vegetation cover, forest stand structure, and tree characteristics may be more important for providing visual concealment or optimal foraging conditions. However, it remains possible that such factors also convey olfactory concealment. For example, savannah-like forests preferred by RCWs may have greater air turbulence than closed forests. Further research on RCWs and other bird species to address additional aspects of olfactory concealment, and relationships between different dimensions of concealment (e.g., between visual and olfactory concealment), would give insight into how habitat management could provide multiple benefits to birds.

Asymmetric Orientation Combination for Reversible and Authenticable Data Hiding of Dual Stego-images

A dual-image-based reversible data hiding (RDH) scheme can conceal secret data into a cover image by creating two steganographic images. These two stego-images can cooperate to extract secret data and restore the cover image. This paper describes a generalization of the orientation combination technology for dual-image-based RDH. We first propose a full search algorithm to find the optimal set of the reversible orientation combinations. Based on the algorithm, the modification range of pixel values can be dynamically enlarged, and thus the embedding capacity becomes adjustable. In addition, an authentication algorithm is provided to detect tampered shadows based on a faithful one. Experimental results confirm that the proposed scheme can produce dual stego-images with a good visual quality. Furthermore, our method provides an adjustable payload. A lot more secret data can be embedded than with state-of-the-art methods, with a satisfactory image quality. Two steganalysis tools are applied to demonstrate the security level of the proposed scheme.

Unidirectional collective transport of microspheres in nematic liquid crystal by electrically tunable reorientation

Manipulation of microparticles in dispersion medium has attracted a widespread attention, with applications ranging from microfluidic physics to engineering. At present, manipulating microparticles unidirectionally along the direction perpendicular to the electric field remains a challenge. In this work, we designed a liquid crystal cell with an opposite pretilt orientation to transport the silica spheres with diameters of several microns. We investigated the effect of field parameters on the transport velocity of microspheres, mechanism of the unidirectional collective transport, and motion behaviors in the case of collision. The results show that, depending on the field intensity and modulation frequency, the transport velocity varies from a few to more than 100 μm/s. The microspheres move to the opposite side of rubbing direction, and it can be adjusted by changing the alignment layer’s orientation direction. The proposed cell structure is simple, and the microspheres do not require surface modifications. Both these factors facilitate the high-throughput transport of micro-cargoes.

Topological Green function of interacting systems

We construct a Green function, which can identify the topological nature of interacting systems. It is equivalent to the single-particle Green function of effective non-interacting particles, the Bloch Hamiltonian of which is given by the inverse of the full Green function of the original interacting particles at zero frequency. The topological nature of the interacting insulators is originated from the coincidence of the poles and the zeros of the diagonal elements of the constructed Green function. The cross of the zeros in the momentum space closely relates to the topological nature of insulators. As a demonstration, using the zero's cross, we identify the topological phases of magnetic insulators, where both the ionic potential and the spin exchange between conduction electrons and magnetic moments are present together with the spin-orbital coupling. The topological phase identification is consistent with the topological invariant of the magnetic insulators. We also found an antiferromagnetic state with topologically breaking of the spin symmetry, where electrons with one spin orientation are in topological insulating state, while electrons with the opposite spin orientation are in topologically trivial one.

The Direct Reproductive Cost of Same-Sex Attraction: Evidence from Two Nationally Representative U.S. Samples.

Same-sex attraction is associated with a direct reproductive cost, i.e., a reduced number of biological children. The current study aimed to assess this cost for different forms of sexual attraction (i.e., only attracted to opposite sex, mostly attracted to opposite sex, equally attracted to both sexes, mostly attracted to same-sex, only attracted to same-sex), using two large nationally representative datasets (N = 15,208) from the USA. The results indicated that same-sex attraction was associated with substantial loss in direct reproductive output. More specifically, significant differences between the different types of same-sex attraction were found: Exclusive and mostly homosexual orientation identities were associated with the highest direct reproductive cost, while mostly attracted to opposite sex orientation and bisexuality identities were associated with lower direct reproductive costs. In addition, bisexual women did not differ significantly from exclusively heterosexual women in terms of their reproductive output. The implications of these findings for the evolutionary origins of same-sex attraction are further discussed.

Charge and spin supercurrents in magnetic Josephson junctions with spin filters and domain walls

We analyze theoretically the influence of domain walls (DWs) on the DC Josephson current in magnetic superconducting S$_{m}$/Fl/F/Fl/S$_{m}$ junctions. The Josephson junction consists of two "magnetic" superconductors S$_{m}$ (superconducting film covered by a thin ferromagnetic layer), spin filters Fl and a ferromagnetic layer F with or without DW (DWs). The spin filters Fl allow electrons to pass with one specific spin orientation, such that the Josephson coupling is governed by a fully polarized long-range triplet component. In the absence of DW(s), the Josephson and spin currents are nonzero when the right and left filters, Fl$_{r,l}$, pass electrons with equal spin orientation and differ only by a temperature-independent factor. They become zero when the \textbf{spins} of the triplet Cooper pairs passing through the Fl$_{r,l}$ have opposite directions. Furthermore, for the different chiralities of the injected triplet Cooper pairs the spontaneous currents arise in the junction yielding a diode effect. Once a DW is introduced, it reduces the critical Josephson current $I_{c}$ in the case of equal spin polarization and makes it finite in the case of opposite spin orientation. The critical current $I_{c}$ is maximal when the DW is in the center of the F film. A deviation of the DW from the center generates a force that pushes the DW to the center of the F film. In addition, we consider the case of an arbitrary number $N$ of DW's, with the case $N=2$ corresponding to a model system for a magnetic skyrmion.

Mechanisms of loading and release of the 9-1-1 checkpoint clamp.

Single-stranded or double-stranded DNA junctions with recessed 5' ends serve as loading sites for the checkpoint clamp, 9-1-1, which mediates activation of the apical checkpoint kinase, ATRMec1. However, the basis for 9-1-1's recruitment to 5' junctions is unclear. Here, we present structures of the yeast checkpoint clamp loader, Rad24-replication factor C (RFC), in complex with 9-1-1 and a 5' junction and in a post-ATP-hydrolysis state. Unexpectedly, 9-1-1 adopts both closed and planar open states in the presence of Rad24-RFC and DNA. Moreover, Rad24-RFC associates with the DNA junction in the opposite orientation of processivity clamp loaders with Rad24 exclusively coordinating the double-stranded region. ATP hydrolysis stimulates conformational changes in Rad24-RFC, leading to disengagement of DNA-loaded 9-1-1. Together, these structures explain 9-1-1's recruitment to 5' junctions and reveal new principles of sliding clamp loading.

A Renewed Appreciation of Helicoverpa armigera Nucleopolyhedrovirus BJ (Formerly Helicoverpa assulta Nucleopolyhedrovirus) with Whole Genome Sequencing.

Helicoverpa assulta is a pest that causes severe damage to tobacco, pepper and other cash crops. A local strain of HearNPV-BJ (formerly Helicoverpa assulta nucleopolyhedrovirus (HeasNPV-DJ0031)) was isolated from infected H. assulta larvae in Beijing, which had been regarded as a new kind of baculovirus in previous studies. Describing the biological characteristics of the strain, including its external morphology, internal structure and the pathological characteristics of the infection of various cell lines, can provide references for the identification and function of the virus. HearNPV-BJ virion was defined as a single-nucleocapsid nucleopolyhedrovirus by scanning electron microscopy. QB-Ha-E-5 (H. armigera) and BCIRL-Hz-AM1 (H. zea) cell lines were sensitive to HearNPV-BJ. Undoubtedly modern developed sequencing technology further facilitates the increasing understanding of various strains. The whole genome sequence of the HearNPV-BJ was sequenced and analyzed. The HearNPV-BJ isolate genome was 129, 800 bp nucleotides in length with a G + C content of 38.87% and contained 128 open reading frames (ORFs) encoding predicted proteins of 50 or over 50 amino acids, 67 ORFs in the forward orientation and 61 ORFs in the reverse orientation, respectively. The genome shared 99% sequence identity with Helicoverpa armigera nucleopolyhedrovirus C1 strain (HearNPV-C1), and 103 ORFs had very high homology with published HearNPV sequences. Two bro genes and three hrs were found to be dispersed along the HearNPV-BJ genome. Three of the highest homologs, ORFs with HearNPV, were smaller due to the earlier appearance of the stop codon with unknown functions. P6.9 of HearNPV-BJ, a structural protein, is distinctly different from that of Autographa californica nucleopolyhedrovirus (AcMNPV); its homology with the corresponding gene in HearNPV-C1 was 93.58%. HearNPV-BJ contains 38 core genes identified in other baculoviruses, and phylogenetic analysis indicates HearNPV-BJ belongs to Alphabaculovirus Group II, same as HearNPV-C1. The resulting data provide a better understanding of virion structure, gene function and character of infection. By supplementing the whole-genome sequencing data and Kimura-2 model index, there is more evidence to indicate that HearNPV-BJ may be a variant of Helicoverpa armigera nucleopolyhedrovirus, which also deepens our understanding of the virus species demarcation criteria.

Gradient Architecture Design in Scalable Porous Battery Electrodes.

Because it has been demonstrated to be effective toward faster ion diffusion inside the pore space, low-tortuosity porous architecture has become the focus in thick electrode designs, and other possibilities are rarely investigated. To advance current understanding in the structure-affected electrochemistry and to broaden horizons for thick electrode designs, we present a gradient electrode design, where porous channels are vertically aligned with smaller openings on one end and larger openings on the other. With its 3D morphology carefully visualized by Raman mapping, the electrochemical properties between opposite orientations of the gradient electrodes are compared, and faster energy storage kinetics is found in larger openings and more concentrated active material near the separator. As further verified by simulation, this study on gradient electrode design deepens the knowledge of structure-related electrochemistry and brings perspectives in high-energy battery electrode designs.

Cosmology from confinement?

We describe a class of holographic models that may describe the physics of certain four-dimensional big-bang/big-crunch cosmologies. The construction involves a pair of 3D Euclidean holographic CFTs each on a homogeneous and isotropic space M coupled at either end of an interval ℐ to a Euclidean 4D CFT on M × ℐ with many fewer local degrees of freedom. We argue that in some cases, when the size of M is much greater than the length of ℐ, the theory flows to a confining three-dimensional field theory on M in the infrared, and this is reflected in the dual description by the asymptotically AdS spacetimes dual to the two 3D CFTs joining up in the IR to give a Euclidean wormhole. The Euclidean construction can be reinterpreted as generating a state of the Lorentzian 4D CFT on M × time whose dual includes the physics of a big-bang/big-crunch cosmology. When M is ℝ3, we can alternatively analytically continue one of the ℝ3 directions to get an eternally traversable four-dimensional planar wormhole. We suggest explicit microscopic examples where the 4D CFT is mathcal{N} = 4 SYM theory and the 3D CFTs are superconformal field theories with opposite orientation. In this case, the two geometries dual to the pair of 3D SCFTs can be understood as a geometrical version of a brane-antibrane pair, and the tendency of the geometries to connect up is related to the standard instability of brane-antibrane systems.

Utopian Ruins: A Memorial Museum of the Mao Era

Utopian Ruins: A Memorial Museum of the Mao Era

Prediction of Plasma Membrane Cholesterol from 7-Transmembrane Receptor Using Hybrid Machine Learning Algorithm

The researches have been made on G-protein coupled receptors (GPCRs) over the long-ago decades. GPCR is also named as 7-transmembrane (7TM) receptor. According to biological prospective GPCRs consist of large protein family with respective subfamilies and are mediated by different physiological phenomena like taste, smell, vision etc. The main functionality of these 7TM receptors is signal transduction among various cells. In human genome, cell membrane plays significant role. All cells are made up of trillion of cells and have dissimilar functionality. Cell membrane composed of different components. GPCRs are reported to be modulated by membrane cholesterol by interacting with cholesterol recognition amino acid consensus (L/V-X (1-5)-Y-X (1-5)-R/K) (CRAC) or reverse orientation of CRAC (R/K-X (1-5)-Y-X (1-5)-L/V) (CARC) motifs present in the TM helices. Among all, cholesterol is one who is regulated by membrane proteins. Here we took GPCR as membrane proteins and this protein modulates membrane cholesterol. According to cell biology, GPCR regulates a wide diversity of vital cellular processes and are targeted by a huge fraction of approved drugs. In this paper we have concentrated our investigation on membrane protein with membrane cholesterol. A hybrid algorithm consisting of spectral clustering and support vector machine is proposed for prediction of membrane cholesterol with GPCR. Spectral clustering uses graph nodes for calculating the cluster points and also it considers other concept such as similarity matrix, low-dimensional space for projecting the data points and upon this parameter at last construct the cluster centre. Supervised learning method is used for solving regression and classification problems. From the analysis we found that our result shows better prediction accuracy in terms of time complexity when compared with two existing models such as fuzzy c-means (FCM) and rough set with FCM model

Deferred Polarization Saturation Boosting Superior Energy-Storage Efficiency and Density Simultaneously under Moderate Electric Field in Relaxor Ferroelectrics

High-temperature dielectric Bi0.5Na0.5TiO3 (BNT)-based relaxors near a morphotropic phase boundary are developed with excellent energy storage performance. Random distribution of polar nanoregions induced by composition modulation would disrupt the ferroelectric long-range dipolar alignment and weaken the coupling between the ferroelectric domains, yielding slender and deferred polarization–electric field hysteresis loops with relatively high saturation polarization. The reversible nano-domain orientation and growth in relaxors under a delayed electric field result in negligible remnant polarization and advantageous energy storage properties. Simultaneously, superior recoverable energy storage density and efficiency are gained, significantly surpassing the state-of-the-art dielectric energy storage materials under similar moderate electric fields. Vacancies, defect dipole behavior, and structural evolution that relied on an electric field and temperature are discussed to disclose the underlying mechanism associated with phase transition. Even thermal stability and large electrostrictive strain with low hysteresis are achieved in elevated temperatures. These features demonstrate the promising candidates for dielectric energy-storage application and provide a strategy in designing relaxors.

A constructive method for parabolic equations with opposite orientations arising in optimal control

An optimal control model governed by parabolic equations is usually analyzed by carrying out the formulation of the so called “optimality system”, that consists of equations with opposite orientations. PDE-constrained optimization is employed in different fields, such as in economics and in ecology for allocating resources and managing ecosystems. Under the assumption that any solution exists, we provide an original proof of its uniqueness. This result is original and can be applied to a wide range of problems. Moreover, the same proof can be exploited to carry out a constructive method for approximating the solution, which is not available in closed form in the most cases. The method is based on successive approximations converging to a fixed-point that is the required solution. Due to the structure of the problem, this kind of approximation performs a forward-backward integration, giving raise to different iterative schemes. We investigate their convergence in the continuous setting under an original approach, by adapting the same proof provided for the exact solution uniqueness. Another innovative issue is related to the numerical implementation which involves exponential integration in time: up to our knowledge, the use of exponential integrators is new and original in the setting of PDE-constrained optimization. The effectiveness of the proposed approach is shown by providing some numerical results.

Orientation-preserving and orientation-reversing mappings: a new description

We characterise the respective semigroups of mappings that preserve, or that preserve or reverse orientation of a finite cycle, in terms of their actions on oriented triples and oriented quadruples. This leads to a proof that the latter semigroup coincides with the semigroup of all mappings that preserve intersections of chords on the corresponding circle.