Orientation Selectivity Research Articles

Polarization-Sensitive Photodetection of Anisotropic 2D Black Arsenic

A lateral phototransistor structure based on mechanically exfoliated multilayer black arsenic (b-As) is produced to test its in-plane anisotropy of photoelectrical properties. First, the morphology and structure of the b-As flake are investigated with respect to light polarization and crystal structure orientation. Then, the Raman modes, demonstrating a strong anisotropic nature of twofold symmetry for in-plane vibrations and fourfold symmetry for out-of-plane vibrations, allow us to define the armchair and zigzag crystal directions. The lateral photodetector structure has been prepared by depositing polar-oriented electrodes with an angular step of 45° correlated along the b-As crystal directions. Angle-resolved electrical transport and polarization-resolved photocurrent measurements show its strong in-plane anisotropic photoelectrical properties when conductance and photocurrent are about 2 times higher across the armchair direction than the zigzag one. The respective photoresponsivity at 980 nm is 0.44 and 0.19 A/W with the dichroic ratio of 2.3. The intrinsic linear dichroism conversion is responsible for the unique orientation selection behavior in polarization-dependent photodetection. The results show that multilayer b-As is a potentially useful material for application in innovative polarization-sensitive photodetectors.

The influence of printing angle on color and translucency of 3D printed resins for dental restorations.

To evaluate the influence of printing orientation on color and translucency of 3D printing restorative resins. Four 3D printing resin systems in the available shades (DFT-Detax Freeprint Temp- A1, A2,A3; FP-Formlabs Permanent Crown- A2,A3,B1,C2; FT- Formlabs Temporary CB- A2,A3,B1,C2; GCT-GC Temporary- Light, Medium) were evaluated. Three samples (10×10×1.2 mm) from each material were printed at two different printing orientations (0° and 90°) and polished to 1.00±0,01mm of thickness. Spectral reflectance was measured against black background using a calibrated spectroradiometer, CIE D65 standard illuminant and the 45°/0°geometry. Color and translucency differences were evaluated using CIEDE2000 metric (ΔE00) and 50:50% perceptibility (PT00 and TPT00) and acceptability (AT00 and TAT00) thresholds. In general, color changes due to printing orientation at (0° and 90°) were mainly produced by ΔL*or ΔC*. ΔE00 were above PT00 for all DFT shades, FP-B1, FP-C2, FT-A2 and FT-B1. Only for DFT-1, ΔE00 was above AT00. ΔRTP00 values were above TPT00 for DFT-A1, DFT-A3, FP-B1 and FT-B1, but lower than TAT00. The direction of the changes in translucency (ΔRTP00) depends on the material and shade. The selection of building orientation (0° and 90°) for the 3D printed resins influence the visual color and translucency and therefore their esthetic appearance. These aspects should be considered when printing dental restorations using the evaluated materials.

The Coupling and Coordination and Orientation Selection of Green Finance and Green Agriculture Development in Anhui Province

In recent years, China has continuously introduced policies and measures to solve the problems of agriculture, rural areas and farmers, improve people's livelihood, and enhance farmers' happiness. Green agriculture and green finance system are both dynamic, open and relatively complex integrated systems, which promote and interact with each other. The index system based on the development of green agriculture and green finance is established, using the entropy method and coupling coordination model, the comprehensive index of the development of green agriculture and green finance in Anhui Province, and the coupling degree and coupling coordination degree between the two systems are calculated. The research suggests that we should increase the policy support for the coordinated development of green agriculture and green finance, and accelerate the feasible path of the development of Anhui province.

A quantitative study of the effect of ICL orientation selection on post-operative vault and model-assisted vault prediction.

Appropriate vault height of implantable collamer lens (ICL) implantation matters for it has risks of corneal endothelial cell loss, cataract formation and intraocular pressure elevation, which could lead to irreversible damage to optic nerve. Therefore, pre-operative prediction for an ideal vault height is a hotspot. However, few data exist regarding quantitative effect of ICL orientation on vault height. This study is aimed to quantitatively investigate the effect of ICL implantation orientation on vault height, and built a machine-learning (ML)-based vault prediction model taking implantation orientation into account. 473 consecutive case series treated with ICL implantation were retrospectively analyzed (408 were horizontally implanted, and 65 were vertically implanted). Multivariable logistic regression analysis was performed to determine the association between ICL orientation and achieved vault. ML was performed to develop a new vault height prediction model taking ICL orientation into account. Receiver operating characteristic curve (ROC) and net reclassification index (NRI) were obtained to assess the prediction ability. 95% of all the patients achieved 20/20 uncorrected distance visual acuity (UDVA) or better. No complications including cataract formation, dispersion or optic nerve injury were observed in any cases. Sex, sphere power, cylinder power, axis, ICL size and ICL orientation were all significant risk factors associated to vault height, and age was positively co-related. Of note, ICL size and ICL orientation were the top-ranking risk factors. Comparing to conventional horizontal implantation, vertical implantation could reduce the achieved vault by 81.187 μm (p < 0.001). In regarding to different ICL sizes, vertical implantation had no good to vault reduction when using ICL of 12.1 mm. However, it could reduce the vault by 59.351 μm and 160.992 μm respectively when ICL of 12.6mm and 13.2 mm were implanted (p = 0.0097 and p = 0.0124). For prediction of vault height, ML based model significantly outperformed traditional multivariable regression model. We provide quantitative evidence that vertical implantation of ICL could effectively reduce the achieved vault height, especially when large size ICL was implanted, comparing to traditional horizontal implantation. ML is extremely applicable in development of vault prediction model.

Expectation violations enhance neuronal encoding of sensory information in mouse primary visual cortex

The response of cortical neurons to sensory stimuli is shaped both by past events (adaptation) and the expectation of future events (prediction). Here we employed a visual stimulus paradigm with different levels of predictability to characterise how expectation influences orientation selectivity in the primary visual cortex (V1) of male mice. We recorded neuronal activity using two-photon calcium imaging (GCaMP6f) while animals viewed sequences of grating stimuli which either varied randomly in their orientations or rotated predictably with occasional transitions to an unexpected orientation. For single neurons and the population, there was significant enhancement in the gain of orientation-selective responses to unexpected gratings. This gain-enhancement for unexpected stimuli was prominent in both awake and anaesthetised mice. We implemented a computational model to demonstrate how trial-to-trial variability in neuronal responses were best characterised when adaptation and expectation effects were combined.

Selection of Norwegian police drone operators: an evaluation of selected cognitive tests from “The Vienna Test System”

ABSTRACT A nationwide sample of 129 police officers participated in a study aimed at validating and presenting practical implications of a selection procedure for applicants to an educational program for Norwegian police drone pilots. The subjects were part of a selection program for a training and qualification course for police drone pilots. The selection program consisted of tests of spatial orientation, logical reasoning, attentional selection, sustained attention, and visual short-term memory, in addition to a performance test in a drone flight simulator. The aim of the study was to evaluate the cognitive tests used in the selection program and their relation to performance during the simulated flight. The results from the untrained applicants revealed low-to-moderate intercorrelations of the cognitive tests. Only spatial orientation, logical reasoning, and attentional selection were correlated to the performance measures of skills and proficiency. Stepwise regression analysis showed that only spatial orientation and attentional selection had unique contributions in explaining the variance in both measures of performance. Implications are discussed on both practical and scientific levels. The positive implications of using untrained respondents, the use of proficiency measures in addition to skills, the building of a clearinghouse for drone selection data, and considering both the job-analyzes and the total test-performance when interpreting the applicant’s test-scores are discussed.

Model-Based Approach Shows ON Pathway Afferents Elicit a Transient Decrease of V1 Responses.

Neurons in the primary visual cortex (V1) receive excitation and inhibition from distinct parallel pathways processing lightness (ON) and darkness (OFF). V1 neurons overall respond more strongly to dark than light stimuli, consistent with a preponderance of darker regions in natural images, as well as human psychophysics. However, it has been unclear whether this "dark-dominance" is because of more excitation from the OFF pathway or more inhibition from the ON pathway. To understand the mechanisms behind dark-dominance, we record electrophysiological responses of individual simple-type V1 neurons to natural image stimuli and then train biologically inspired convolutional neural networks to predict the neurons' responses. Analyzing a sample of 71 neurons (in anesthetized, paralyzed cats of either sex) has revealed their responses to be more driven by dark than light stimuli, consistent with previous investigations. We show that this asymmetry is predominantly because of slower inhibition to dark stimuli rather than to stronger excitation from the thalamocortical OFF pathway. Consistent with dark-dominant neurons having faster responses than light-dominant neurons, we find dark-dominance to solely occur in the early latencies of neurons' responses. Neurons that are strongly dark-dominated also tend to be less orientation-selective. This novel approach gives us new insight into the dark-dominance phenomenon and provides an avenue to address new questions about excitatory and inhibitory integration in cortical neurons.SIGNIFICANCE STATEMENT Neurons in the early visual cortex respond on average more strongly to dark than to light stimuli, but the mechanisms behind this bias have been unclear. Here we address this issue by combining single-unit electrophysiology with a novel machine learning model to analyze neurons' responses to natural image stimuli in primary visual cortex. Using these techniques, we find slower inhibition to light than to dark stimuli to be the leading mechanism behind stronger dark responses. This slower inhibition to light might help explain other empirical findings, such as why orientation selectivity is weaker at earlier response latencies. These results demonstrate how imbalances in excitation versus inhibition can give rise to response asymmetries in cortical neuron responses.

Hierarchical retinal computations rely on hybrid chemical-electrical signaling.

Bipolar cells (BCs) are integral to the retinal circuits that extract diverse features from the visual environment. They bridge photoreceptors to ganglion cells, the source of retinal output. Understanding how such circuits encode visual features requires an accounting of the mechanisms that control glutamate release from bipolar cell axons. Here, we demonstrate orientation selectivity in a specific genetically identifiable type of mouse bipolar cell-type 5A (BC5A). Their synaptic terminals respond best when stimulated with vertical bars that are far larger than their dendritic fields. We provide evidence that this selectivity involves enhanced excitation for vertical stimuli that requires gap junctional coupling through connexin36. We also show that this orientation selectivity is detectable postsynaptically in direction-selective ganglion cells, which were not previously thought to be selective for orientation. Together, these results demonstrate how multiple features are extracted by a single hierarchical network, engaging distinct electrical and chemical synaptic pathways.

Structural and functional integration of human forebrain organoids with the injured adult rat visual system.

Brain organoids created from human pluripotent stem cells represent a promising approach for brain repair. They acquire many structural features of the brain and raise the possibility of patient-matched repair. Whether these entities can integrate with host brain networks in the context of the injured adult mammalian brain is not well established. Here, we provide structural and functional evidence that human brain organoids successfully integrate with the adult rat visual system after transplantation into large injury cavities in the visual cortex. Virus-based trans-synaptic tracing reveals a polysynaptic pathway between organoid neurons and the host retina and reciprocal connectivity between the graft and other regions of the visual system. Visual stimulation of host animals elicits responses in organoid neurons, including orientation selectivity. These results demonstrate the ability of human brain organoids to adopt sophisticated function after insertion into large injury cavities, suggesting a translational strategy to restore function after cortical damage.

Effect of dimensional variations on the manufacturing process and the 3D shrinkage ratio of stereolithographic dental alumina ceramics.

The purpose of the present study was to evaluate the influence of height and length variations of alumina ceramics manufactured by stereolithography on deformations caused by the manufacturing process and on the 3D shrinkage ratio to control the final dimensions and improve the adaptation of stereolithographic ceramic dental prostheses. Two different U-shaped models were designed with variable heights or lengths. The specimens were manufactured by stereolithography and were scanned using a microtomographic device before and after the heat treatment. Dimensional variations were measured using inspection software. The number and surface of layers of alumina ceramic influenced the reliability of the stereolithography manufacturing but did not influence the 3D shrinkage ratio. The larger the layer surface, the larger the deformation of the ceramic. Dental ceramics manufactured by stereolithography with smallest layer surface are the most reliable. This helps in the selection of the build orientation.

Paired optogenetic and visual stimulation can change the orientation selectivity of visual cortex neurons

Synaptic plasticity is currently considered the main mechanism underlying the plastic modification of neural networks. The vast majority of studies of synaptic plasticity are carried out on reduced preparations, but the situation in vivo is fundamentally different from that in vitro. In this work, we used the Hebbian paradigm, which is known to induce long-term changes in synaptic strength in vitro, to manipulate the properties of a single pyramidal neuron in the mouse visual cortex. We have shown that optogenetic stimulation of a ChR2-expressing pyramidal neuron in the primary visual cortex of Thy-ChR2 mice paired with the presentation of a visual stimulus of non-optimal orientation induces long-term changes in the properties of the receptive field, manifested in alteration of the orientation selectivity of the cell. Non-paired stimulation did not lead to changes in the properties of the receptive field of the neuron during the experiment. Thus, we have demonstrated the role of associative plasticity in the dynamic organization of the receptive fields of neurons in the visual cortex.

Hygrothermal dynamic behavior of fiber metal laminated structure under dual-ellipse distribution heat source

Refined plate theory could account for parabolic variation of transverse shear stress through the thickness, and satisfy the zero traction boundary conditions on the top and bottom surfaces of the plate without introducing shear correction factor, of which all displacement variables can be depicted in functions of shear and bending components. Based on three-dimensional transient thermal conduction theory and the refined plate theory, an analytical solution of fiber metal laminated (FML) plate under hygrothermal environment is presented. In present work, distinct from other literatures, the separate variable method and Newton-Cotes method is applied to solve the three-dimensional transient temperature field (subjected to moving dual-ellipse distribution laser heat source) firstly. Secondly, the constitutive equations and geometrical equations are derived. Subsequently, the governing equations in hygrothermal environment are obtained. Finally, the Newmark method and Galerkin method are used to solve the governing equations of which in terms of displacement functions. The results show that fiber orientation affects the bending stiffness, the selection of (45°/ 0°) fiber orientation is more resistance to deformation and normal stress, and bending part is more sensitive to shear factor between layers.

Critical Role of Surface Termination of Sapphire Substrates in Crystallographic Epitaxial Growth of MoS2 Using Inorganic Molecular Precursors.

A highly reproducible route for the epitaxial growth of single-crystalline monolayer MoS2 on a C-plane sapphire substrate was developed using vapor-pressure-controllable inorganic molecular precursors MoOCl4 and H2S. Microscopic, crystallographic, and spectroscopic analyses indicated that the epitaxial MoS2 film possessed outstanding electrical and optical properties, excellent homogeneity, and orientation selectivity. The systematic investigation of the effect of growth temperature on the crystallographic orientations of MoS2 revealed that the surface termination of the sapphire substrate with respect to the growth temperature determines the crystallographic orientation selectivity of MoS2. Our results suggest that controlling the surface to form a half-Al-terminated surface is a prerequisite for the epitaxial growth of MoS2 on a C-plane sapphire substrate. The insights on the growth mechanism, especially the significance of substrate surface termination, obtained through this study will aid in designing efficient epitaxial growth routes for developing single-crystalline monolayer transition metal dichalcogenides.

Efficient sampling of molecular orientations for Cu(II)-based DEER on protein labels.

Combining rigid Cu(II) labels and pulsed-EPR techniques enables distance constraint measurements that are incisive probes of protein structure and dynamics. However, the labels can lead to a dipolar signal that is biased by the relative orientation of the two spins, which is typically unknown a priori in a bilabeled protein. This effect, dubbed orientational selectivity, becomes a bottleneck in measuring distances. This phenomenon also applies to other pulsed-EPR techniques that probe electron-nucleus interactions. In this work, we dissect orientational selectivity by generating an in silico sample of Cu(II)-labeled proteins to evaluate pulse excitation in the context of double electron-electron resonance (DEER) at Q-band frequencies. This approach enables the observation of the contribution of each protein orientation to the dipolar signal, which provides direct insights into optimizing acquisition schemes to mitigate orientational effects. Furthermore, we incorporate the excitation profile of realistic pulses to identify the excited spins. With this method, we show that rectangular pulses, despite their imperfect inversion capability, can sample similar spin orientations as other sophisticated pulses with the same bandwidth. Additionally, we reveal that the efficiency of exciting spin-pairs in DEER depends on the frequency offset of two pulses used in the experiment and the relative orientation of the two spins. Therefore, we systematically examine the frequency offset of the two pulses used in this double resonance experiment to determine the optimal frequency offset for optimal distance measurements. This procedure leads to a protocol where two measurements are sufficient to acquire orientational-independent DEER at Q-band. Notably, this procedure is feasible with any commercial pulsed-EPR spectrometer. Furthermore, we experimentally validate the computational results using DEER experiments on two different proteins. Finally, we show that increasing the amplitude of the rectangular pulse can increase the efficiency of DEER experiments by almost threefold. Overall, this work provides an attractive new approach for analyzing pulsed-EPR spectroscopy to obtain microscopic nuances that cannot be easily discerned from analytical or numerical calculations.

ОБЕСПЕЧЕНИЕ БЕЗОПАСНОЙ ЖИЗНЕДЕЯТЕЛЬНОСТИ РАБОТНИКОВ ГОРНОЙ ПРОМЫШЛЕННОСТИ

The necessity of creating conditions for the safe life of mining workers through the development of sports in order to diagnose and minimize health risks is substantiated. The method of identifying the sports predisposition of people based on the methods of correct sports selection of sports activities and sports orientation is proposed. The approbation of the methodology was carried out, as a result of which, within the framework of the study, a group of participants was identified, in relation to which recommendations were formed on limiting sports activities due to the presence of high health risks. A financial assessment of the risks of life has been carried out and proposals have been developedfor the use of a methodology for identifying sports predisposition as a tool for managing the safe life of mining workers.

OMIRD: Orientated Modality Independent Region Descriptor for Optical-to-SAR Image Matching

Image matching between optical and SAR images remains challenging due to their different imaging principles. Despite recent developments in image matching methods for optical-to-SAR images, few have seen practical application success due to the significant geometric and radiometric differences between the two modalities. In this letter, we propose a new method called the Orientated Modality Independent Region Descriptor (OMIRD) to overcome these challenges. Our template-based approach effectively extracts consistent structural and textural features from both optical and SAR images. Additionally, we introduce a principal orientation selection method, using the Ratio of Exponentially Weighted Averages (ROEWA) and logarithm Histogram of Gradient (HOG) to identify the most meaningful feature orientations and further simplify the OMIRD descriptor. The experimental results indicate that the proposed OMIRD exhibits superior matching accuracy and robustness under various geometric distortions and non-linear grayscale variations.

Stable spontaneous orientation polarization by widening the optical band gap with 1,3,5,7-tetrakis(1-phenyl-1H-benzo[d]imidazol-2-yl)adamantane

1,3,5,7-Tetrakis(1-phenyl-1H-benzo[d]imidazol-2-yl)adamantane exhibits large and stable surface orientation polarization in vacuum-deposited films due to the subtle orientation selectivity of the molecule and the non-conjugated adamantane core.

Locking water molecules via ternary O-H⋯O intramolecular hydrogen bonds in perhydroxylated closo-dodecaborate.

A multitude of applications related to perhydroxylated closo-dodecaborate B12(OH)122- in the condensed phase are inseparable from the fundamental mechanisms underlying the high water orientation selectivity based on the base B12(OH)122-. Herein, we directly compare the structural evolution of water clusters, ranging from monomer to hexamer, oriented by functional groups in the bases B12H122-, B12H11OH2- and B12(OH)122- using multiple theoretical methods. A significant revelation is made regarding B12(OH)122-: each additional water molecule is locked into the intramolecular hydrogen bond B-O-H ternary ring in an embedded form. This new pattern of water cluster growth suggests that B-(H-O)⋯H-O interactions prevail over the competition from water-hydrogen bonds (O⋯H-O), distinguishing it from the behavior observed in B12H122- and B12H11OH2- bases, in which competition arises from a mixed competing model involving dihydrogen bonds (B-H⋯H-O), conventional hydrogen bonds (B-(H-O)⋯H-O) and water hydrogen bonds (O⋯H-O). Through aqueous solvation and ab initio molecular dynamics analysis, we further demonstrate the largest water clusters in the first hydrated shell with exceptional thermodynamic stability around B12(OH)122-. These findings provide a solid scientific foundation for the design of boron cluster chemistry incorporating hydroxyl-group-modified borate salts with potential implications for various applications.

Effect of fiber orientation and loading direction on the compressive response of E-glass/Epoxy laminated composites used in modern helicopter blades submitted to high strain rate

In this investigation, the dynamic behaviour of glass fibre reinforced poly- mer under in-plane and out-of-plane dynamic compression tests was studied experimentally and numerically under varying the fibres orientation and the loading conditions. The composites consist of unidirectional E-glass fibers reinforced epoxy polymer composites used in modern helicopter blade application as inner surface. Specimens, with a cylindrical shape, are impacted at a constant strain rate subjected to SHPB and Ls Dyna program. The numerical results are in good agreement with experimental results. The results show that the out-of-plane stress values for different fiber orientation are close to each other, but the in-plane stress value is far lower for the fibers direction of ±45◦. This study will facilitate fiber orientation selection for dynamic effects during the helicopter blade production phase. Not only simple tests but also practical ideas make this study stand out. Considering results, the use of ±90◦ fiber direction in helicopter blades seems to be more advantageous against dynamic effects.

Haploinsufficiency of Shank3 increases the orientation selectivity of V1 neurons

Autism spectrum disorder (ASD) is a neurodevelopmental disorder whose hallmarks are social deficits, language impairment, repetitive behaviors, and sensory alterations. It has been reported that patients with ASD show differential activity in cortical regions, for instance, increased neuronal activity in visual processing brain areas and atypical visual perception compared with healthy subjects. The causes of these alterations remain unclear, although many studies demonstrate that ASD has a strong genetic correlation. An example is Phelan–McDermid syndrome, caused by a deletion of the Shank3 gene in one allele of chromosome 22. However, the neuronal consequences relating to the haploinsufficiency of Shank3 in the brain remain unknown. Given that sensory abnormalities are often present along with the core symptoms of ASD, our goal was to study the tuning properties of the primary visual cortex to orientation and direction in awake, head-fixed Shank3+/− mice. We recorded neural activity in vivo in response to visual gratings in the primary visual cortex from a mouse model of ASD (Shank3+/− mice) using the genetically encoded calcium indicator GCaMP6f, imaged with a two-photon microscope through a cranial window. We found that Shank3+/− mice showed a higher proportion of neurons responsive to drifting gratings stimuli than wild-type mice. Shank3+/− mice also show increased responses to some specific stimuli. Furthermore, analyzing the distributions of neurons for the tuning width, we found that Shank3+/− mice have narrower tuning widths, which was corroborated by analyzing the orientation selectivity. Regarding this, Shank3+/− mice have a higher proportion of selective neurons, specifically neurons showing increased selectivity to orientation but not direction. Thus, the haploinsufficiency of Shank3 modified the neuronal response of the primary visual cortex.