Generation of parthenocarpic tomato plants in multiple elite cultivars using the CRISPR/Cas9 system.

Tomato (Solanum lycopersicum L.) is one of the most important crops in the world for its fruit production. Advances in cutting-edge techniques have enabled the development of numerous critical traits related to the quality and quantity of tomatoes. Genetic engineering techniques, such as gene transformation and gene editing, have emerged as powerful tools for generating new plant varieties with superior traits. In this study, we induced parthenocarpic traits in a population of elite tomato (ET) lines. At first, the adaptability of ET lines to genetic transformation was evaluated to identify the best-performing lines by transforming the SlANT1 gene overexpression cassette and then later used to produce the SlIAA9 knockout lines using the CRISPR/Cas9 system. ET5 and ET8 emerged as excellent materials for these techniques and showed higher efficiency. Typical phenotypes of knockout sliaa9 were clearly visible in G0 and G1 plants, in which simple leaves and parthenocarpic fruits were observed. The high efficiency of the CRISPR/Cas9 system in developing new tomato varieties with desired traits in a short period was demonstrated by generating T-DNA-free homozygous sliaa9 knockout plants in the G1 generation. Additionally, a simple artificial fertilization method was successfully applied to recover seed production from parthenocarpic plants, securing the use of these varieties as breeding materials. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-024-01452-1.

Continuous Vat Photopolymerization for Optical Lens Fabrication.

Optical lenses require feature resolution and surface roughness that are beyond most (3D) printing methods. A new continuous projection-based vat photopolymerization process is reported that can directly shape polymer materials into optical lenses with microscale dimensional accuracy (< 14.7 µm) and nanoscale surface roughness (< 20 nm) without post-processing. The main idea is to utilize frustum layer stacking, instead of the conventional 2.5D layer stacking, to eliminate staircase aliasing. A continuous change of mask images is achieved using a zooming-focused projection system to generate the desired frustum layer stacking with controlled slant angles. The dynamic control of image size, objective and imaging distances, and light intensity involved in the zooming-focused continuous vat photopolymerization are systematically investigated. The experimental results reveal the effectiveness of the proposed process. The 3D-printed optical lenses with various designs, including parabolic lenses, fisheye lenses, and a laser beam expander, are fabricated with a surface roughness of 3.4 nm without post-processing. The dimensional accuracy and optical performance of the 3D-printed compound parabolic concentrators and fisheye lenses within a few millimeters are investiagted. These results highlight the rapid and precise nature of this novel manufacturing process, demonstrating a promising avenue for future optical component and device fabrication.

The SLANT Score Predicts Poor Neurologic Outcome in Comatose Survivors of Cardiac Arrest: An External Validation Using a Retrospective Cohort.

BACKGROUND: Hypoxic brain injury is the leading cause of death in comatose patients following resuscitation from cardiac arrest. Neurological outcome can be difficult to prognosticate following resuscitation, and goals of care discussions are often informed by multiple prognostic tools. One tool that has shown promise is the SLANT score, which encompasses five metrics including initial nonshockable rhythm, leukocyte count after targeted temperature management, total adrenaline dose during resuscitation, lack of bystander cardiopulmonary resuscitation, and time to return of spontaneous circulation. This cohort study aimed to provide an external validation of this score by using a database of comatose cardiac arrest survivors from our institution. METHODS: We retrospectively queried our database of cardiac arrest survivors, selecting for patients with coma, sustained return of spontaneous circulation, and use of targeted temperature management to have a comparable sample to the index study. We calculated SLANT scores for each patient and separated them into risk levels, both according to the original study and according to a Youden index analysis. The primary outcome was poor neurologic outcome (defined by a cerebral performance category score of 3 or greater at discharge), and the secondary outcome was in-hospital mortality. Univariable and multivariable analyses, as well as a receiver operator characteristic curve, were used to assess the SLANT score for independent predictability and diagnostic accuracy for poor outcomes. RESULTS: We demonstrate significant association between a SLANT group with increased risk and poor neurologic outcome on univariable (p = 0.005) and multivariable analysis (odds ratio 1.162, 95% confidence interval 1.003-1.346, p = 0.046). A receiver operating characteristic analysis indicates that SLANT scoring is a fair prognostic test for poor neurologic outcome (area under the curve 0.708, 95% confidence interval 0.536-0.879, p = 0.024). Among this cohort, the most frequent SLANT elements were initial nonshockable rhythm (84.5%) and total adrenaline dose ≥ 5 mg (63.9%). There was no significant association between SLANT score and in-hospital mortality (p = 0.064). CONCLUSIONS: The SLANT score may independently predict poor neurologic outcome but not in-hospital mortality. Including the SLANT score as part of a multimodal approach may improve our ability to accurately prognosticate comatose survivors of cardiac arrest.

Multi-GNSS-Weighted Interpolated Tropospheric Delay to Improve Long-Baseline RTK Positioning.

Until now, RTK (real-time kinematic) and NRTK (Network-based RTK) have been the most popular cm-level accurate positioning approaches based on Global Navigation Satellite System (GNSS) signals in real-time. The tropospheric delay is a major source of RTK errors, especially for medium and long baselines. This source of error is difficult to quantify due to its reliance on highly variable atmospheric humidity. In this paper, we use the NRTK approach to estimate double-differenced zenith tropospheric delays alongside ambiguities and positions based on a complete set of multi-GNSS data in a sample 6-station network in Europe. The ZTD files published by IGS were used to validate the estimated ZTDs. The results confirmed a good agreement, with an average Root Mean Squares Error (RMSE) of about 12 mm. Although multiplying the unknowns makes the mathematical model less reliable in correctly fixing integer ambiguities, adding a priori interpolated ZTD as quasi-observations can improve positioning accuracy and Integer Ambiguity Resolution (IAR) performance. In this work, weighted least-squares (WLS) were performed using the interpolation of ZTD values of near reference stations of the IGS network. When using a well-known Kriging interpolation, the weights depend on the semivariogram, and a higher network density is required to obtain the correct covariance function. Hence, we used a simple interpolation strategy, which minimized the impact of altitude variability within the network. Compared to standard RTK where ZTD is assumed to be unknown, this technique improves the positioning accuracy by about 50%. It also increased the success rate for IAR by nearly 1.

Improved submucosal tunneling endoscopic resection with slant tunnel for submucosal tumors in proximal esophagus.

BACKGROUND: The improved submucosal tunneling endoscopic resection (STER) with slant tunnel was created by our group innovatively for submucosal tumors (SMTs) in the proximal esophagus. This study aimed to provide the preliminary results of the improved STER from our center. METHODS: The key step of the improved STER is establishing a slant tunnel instead of a vertical tunnel. After a longitudinal incision was made proximally in the inclined top to the tumor, a submucosal tunnel was established from the incision to the SMT slantingly. 28 patients undergoing STER with slant tunnel were enrolled in the retrospective study. Clinical results including en bloc resection, curative resection and complication were collected. RESULTS: All the submucous tumors located at proximal esophagus originated from muscularis propria were successfully resected by the innovative STER. Tumor size ranged from 18-43 mm, with 96.4% (27/28) en bloc resection rate and 92.9% (26/28) curative rate. Three patients suffered complication, 1 patient with mild pleural effusion and another 2 patients with fever for one day. All of the complications were cured by conservative treatment. CONCLUSIONS: STER with slant tunnel seems to provide an optional treatment for tumors in proximal esophagus.

Influence of Perceptual-Motor Calibration on the Perception of Geographical Slope.

Individuals drastically overestimate geographic slant. Research has suggested this occurs as the amount of energy it would take to ascend the slope modulates the perceived steepness. Numerous studies have provided evidence that alterations in current physiological potential can influence perceptions of geographical slant. However, it is unclear whether these influences are solely due to one's actual physiological state or whether anticipation of energy expenditure also influences perceived slope. To investigate this, we manipulated anticipated energy expenditure while maintaining actual physiological state by altering the coupling between optic flow and gait. Using virtual reality, we calibrated individuals to either large changes (low anticipated expenditure) or small changes (large anticipated expenditure) in optic flow when walking at the same speed. Following optic flow calibration, individuals estimated slopes of various degrees. The results obtained provide evidence that perceptions of geographical slant are influenced by anticipated energy expenditure.

Adaptive Smoothness Constraint Ionospheric Tomography Algorithm.

Ionospheric tomography reconstruction based on global navigation satellite system observations is usually an ill-posed problem. To resolve it, an adaptive smoothness constraint ionospheric tomography algorithm is proposed in this work. The new algorithm performs an adaptive adjustment for the constrained weight coefficients of the tomography system. The computational efficiency and the reconstructed quality of ionospheric imaging are improved by using the new algorithm. A numerical simulation experiment was conducted in order to validate the feasibility and superiority of the algorithm. The statistical results of the reconstructed errors and the comparisons of ionospheric profiles confirmed the superiority of the new algorithm. Finally, the new algorithm was successfully applied to reconstruct three-dimensional ionospheric images under geomagnetic quiet and geomagnetic disturbance conditions over Hunan province. The tomographic results are reasonable and consistent with the general behavior of the ionosphere. The positive and negative phase storm effects are found during geomagnetic storm occurrence.

Real-Time Global Ionospheric Map and Its Application in Single-Frequency Positioning.

The prevalence of real-time, low-cost, single-frequency, decimeter-level positioning has increased with the development of global navigation satellite systems (GNSSs). Ionospheric delay accounts for most errors in real-time single-frequency GNSS positioning. To eliminate ionospheric interference in real-time single-frequency precise point positioning (RT-SF-PPP), global ionospheric vertical total electron content (VTEC) product is designed in the next stage of the International GNSS Service (IGS) real-time service (RTS). In this study, real-time generation of a global ionospheric map (GIM) based on IGS RTS is proposed and assessed. There are three crucial steps in the process of generating a real-time global ionospheric map (RTGIM): estimating station differential code bias (DCB) using the precise point positioning (PPP) method, deriving slant total electron content (STEC) from PPP with raw observations, and modeling global vertical total electron content (VTEC). Experiments were carried out to validate the algorithm's effectiveness. First, one month's data from 16 globally distributed IGS stations were used to validate the performance of DCB estimation with the PPP method. Second, 30 IGS stations were used to verify the accuracy of static PPP with raw observations. Third, the modeling of residuals was assessed in high and quiet ionospheric activity periods. Afterwards, the quality of RTGIM products was assessed from two aspects: (1) comparison with the Center for Orbit Determination in Europe (CODE) global ionospheric map (GIM) products and (2) determination of the performance of RT-SF-PPP with the RTGIM. Experimental results show that DCB estimation using the PPP method can realize an average accuracy of 0.2 ns; static PPP with raw observations can achieve an accuracy of 0.7, 1.2, and 2.1 cm in the north, east, and up components, respectively. The average standard deviations (STDs) of the model residuals are 2.07 and 2.17 TEC units (TECU) for moderate and high ionospheric activity periods. Moreover, the average root-mean-square (RMS) error of RTGIM products is 2.4 TECU for the one-month moderate ionospheric period. Nevertheless, for the high ionospheric period, the RMS is greater than the RMS in the moderate period. A sub-meter-level horizontal accuracy and meter-level vertical accuracy can be achieved when the RTGIM is employed in RT-SF-PPP.

Effects of symmetry, texture, and monocular viewing on geographical slant estimation.

Hills often appear to be steeper than they are. The unusual magnitude of this error has prompted extensive experimentation. The judgment mode, such as verbal vs. action-based measures, the state of the observer - whether exhausted or well rested - all can influence perceived geographical slant. We hold that slant perception is inherently shaky as soon as the slope in question is no longer palpable, that is if it is outside our personal space. To make this point, we have added symmetry, texture, and depression to the list of factors that might modulate slant perception. When the frontal slope of a hill is to be judged, it appears steeper when the side slopes are steep. We have used model hills close to the subject. Their slopes were judged most accurately when binocular stereoscopic vision was permitted. When closing one eye, observers grossly overestimated all slopes. This error was larger for verbal judgments than for judgments made by indicating the slope with their forearm, however, the pattern of the overestimation remained unchanged. Surface texture mattered surprisingly little. Depressed subjects produced exactly the same results as healthy controls. We conclude that in action space and in vista space (outside immediate personal space), slopes are overestimated because the visual system attempts to turn the 2D retinal stimulus into a regular 3D object, akin to the erection tendency (Aufrichtungstendenz) found in diminished or 2D-stimuli. This tendency is inherently instable and can be swayed by a large number of variables.

Degradation of dye wastewater with a photoelectric integration process (MPEC): Microbial fuel cells-assisted dual electrodes thin-film photoelectrocatalytic.

A novel photoelectric integration process (MPEC) was developed to degrade Amaranth. In the MPEC, the output voltage of the microbial fuel cells (MFCs) was used to assist the dual slant-placed electrodes thin-film photocatalytic (PC). With two MFCs connected in series, the MPEC process realized the highest decolorization efficiency. It is close to that of the external bias photoelectrocatalytic (PEC), and 7% higher than that of the self-generated electric field-assisted photoelectrocatalytic (SPEC). The feasibility of MPEC pre-treatment and MFC post-treatment of Amaranth was investigated. The results demonstrated that MPEC pre-treatment of Amaranth could improve its biodegradability. The higher MPEC decolorization efficiency indicated the stronger biodegradability of the obtained intermediates and the higher MFC output voltage. When the MPEC decolorization efficiency was gradually increased to 50%, the removal efficiencies of total Chemical Oxygen Demand (COD) by the MPEC and MFC increased; when the decolorization efficiency was increased above 50%, the removal efficiencies became stable. MPEC enhanced the biodegradability efficiently and was applicable to pre-treat textile wastewater.

A Generalized Chirp-Scaling Algorithm for Geosynchronous Orbit SAR Staring Observations.

Geosynchronous Orbit Synthetic Aperture Radar (GEO SAR) has recently received increasing attention due to its ability of performing staring observations of ground targets. However, GEO SAR staring observation has an ultra-long integration time that conventional frequency domain algorithms cannot handle because of the inaccurately assumed slant range model and existing azimuth aliasing. To overcome this problem, this paper proposes an improved chirp-scaling algorithm that uses a fifth-order slant range model where considering the impact of the "stop and go" assumption to overcome the inaccuracy of the conventional slant model and a two-step processing method to remove azimuth aliasing. Furthermore, the expression of two-dimensional spectrum is deduced based on a series of reversion methods, leading to an improved chirp-scaling algorithm including a high-order-phase coupling function compensation, range and azimuth compression. The important innovations of this algorithm are implementation of a fifth-order order slant range model and removal of azimuth aliasing for GEO SAR staring observations. A simulation of an L-band GEO SAR with 1800 s integration time is used to demonstrate the validity and accuracy of this algorithm.

Generating an image that affords slant perception from stereo, without pictorial cues.

This paper describes an algorithm for generating a planar image that when tilted provides stereo cues to slant, without contamination from pictorial gradients. As the stimuli derived from this image are ultimately intended for use in studies of slant perception under magnification, a further requirement is that the generated image be suitable for high-definition printing or display on a monitor. A first stage generates an image consisting of overlapping edges with sufficient density that when zoomed, edges that nearly span the original scale are replaced with newly emergent content that leaves the visible edge statistics unchanged. A second stage reduces intensity clumping while preserving edges by enforcing a broad dynamic range across the image. Spectral analyses demonstrate that the low-frequency content of the resulting image, which would correspond to the pictorial cue of texture gradient changes under slant, (a) has a power fall-off deviating from 1/f noise (to which the visual system is particularly sensitive), and (b) does not offer systematic cues under changes in scale or slant. Two behavioral experiments tested whether the algorithm generates stimuli that offer cues to slant under stereo viewing only, and not when disparities are eliminated. With a particular adjustment of dynamic range (and nearly so with the other version that was tested), participants viewing without stereo cues were essentially unable to discriminate slanted from flat (frontal) stimuli, and when slant was reported, they failed to discriminate its direction. In contrast, non-stereo viewing of a control stimulus with pictorial cues, as well as stereoscopic observation, consistently allowed participants to perceive slant correctly. Experiment 2 further showed that these results generalized across a population of different stimuli from the same generation process and demonstrated that the process did not substitute biased slant cues.

fMRI Analysis-by-Synthesis Reveals a Dorsal Hierarchy That Extracts Surface Slant.

The brain's skill in estimating the 3-D orientation of viewed surfaces supports a range of behaviors, from placing an object on a nearby table, to planning the best route when hill walking. This ability relies on integrating depth signals across extensive regions of space that exceed the receptive fields of early sensory neurons. Although hierarchical selection and pooling is central to understanding of the ventral visual pathway, the successive operations in the dorsal stream are poorly understood. Here we use computational modeling of human fMRI signals to probe the computations that extract 3-D surface orientation from binocular disparity. To understand how representations evolve across the hierarchy, we developed an inference approach using a series of generative models to explain the empirical fMRI data in different cortical areas. Specifically, we simulated the responses of candidate visual processing algorithms and tested how well they explained fMRI responses. Thereby we demonstrate a hierarchical refinement of visual representations moving from the representation of edges and figure-ground segmentation (V1, V2) to spatially extensive disparity gradients in V3A. We show that responses in V3A are little affected by low-level image covariates, and have a partial tolerance to the overall depth position. Finally, we show that responses in V3A parallel perceptual judgments of slant. This reveals a relatively short computational hierarchy that captures key information about the 3-D structure of nearby surfaces, and more generally demonstrates an analysis approach that may be of merit in a diverse range of brain imaging domains.

Deterministic Migration-Based Separation of White Blood Cells.

Functional and phenotypic analyses of peripheral white blood cells provide useful clinical information. However, separation of white blood cells from peripheral blood requires a time-consuming, inconvenient process and thus analyses of separated white blood cells are limited in clinical settings. To overcome this limitation, a microfluidic separation platform is developed to enable deterministic migration of white blood cells, directing the cells into designated positions according to a ridge pattern. The platform uses slant ridge structures on the channel top to induce the deterministic migration, which allows efficient and high-throughput separation of white blood cells from unprocessed whole blood. The extent of the deterministic migration under various rheological conditions is explored, enabling highly efficient migration of white blood cells in whole blood and achieving high-throughput separation of the cells (processing 1 mL of whole blood less than 7 min). In the separated cell population, the composition of lymphocyte subpopulations is well preserved, and T cells secrete cytokines without any functional impairment. On the basis of the results, this microfluidic platform is a promising tool for the rapid enrichment of white blood cells, and it is useful for functional and phenotypic analyses of peripheral white blood cells.

Perception of Stand-on-ability: Do Geographical Slants Feel Steeper Than They Look?

Past research has shown that haptically perceived surface slant by foot is matched with visually perceived slant by a factor of 0.81. Slopes perceived visually appear shallower than when stood on without looking. We sought to identify the sources of this discrepancy by asking participants to judge whether they would be able to stand on an inclined ramp. In the first experiment, visual perception was compared to pedal perception in which participants took half a step with one foot onto an occluded ramp. Visual perception closely matched the actual maximal slope angle that one could stand on, whereas pedal perception underestimated it. Participants may have been less stable in the pedal condition while taking half a step onto the ramp. We controlled for this by having participants hold onto a sturdy tripod in the pedal condition (Experiment 2). This did not eliminate the difference between visual and haptic perception, but repeating the task while sitting on a chair did (Experiment 3). Beyond balance requirements, pedal perception may also be constrained by the limited range of motion at the ankle and knee joints while standing. Indeed, when we restricted range of motion by wearing an ankle brace pedal perception underestimated the affordance (Experiment 4). Implications for ecological theory were offered by discussing the notion of functional equivalence and the role of exploration in perception.

Humans use predictive kinematic models to calibrate visual cues to three-dimensional surface slant.

When the sensory consequences of an action are systematically altered our brain can recalibrate the mappings between sensory cues and properties of our environment. This recalibration can be driven by both cue conflicts and altered sensory statistics, but neither mechanism offers a way for cues to be calibrated so they provide accurate information about the world, as sensory cues carry no information as to their own accuracy. Here, we explored whether sensory predictions based on internal physical models could be used to accurately calibrate visual cues to 3D surface slant. Human observers played a 3D kinematic game in which they adjusted the slant of a surface so that a moving ball would bounce off the surface and through a target hoop. In one group, the ball's bounce was manipulated so that the surface behaved as if it had a different slant to that signaled by visual cues. With experience of this altered bounce, observers recalibrated their perception of slant so that it was more consistent with the assumed laws of kinematics and physical behavior of the surface. In another group, making the ball spin in a way that could physically explain its altered bounce eliminated this pattern of recalibration. Importantly, both groups adjusted their behavior in the kinematic game in the same way, experienced the same set of slants, and were not presented with low-level cue conflicts that could drive the recalibration. We conclude that observers use predictive kinematic models to accurately calibrate visual cues to 3D properties of world.

Perceptual biases and cue weighting in perception of 3D slant from texture and stereo information.

Multiple cues are typically available for perceiving the 3D slant of surfaces, and slant perception has been used as a test case for investigating cue integration. Previous evidence suggests that texture and stereo slant cues contribute in an optimal Bayesian manner. We tested whether a Bayesian model could also account for perceptual underestimation of slant from texture. One explanation proposed by Todd, Christensen, and Guckes (2010) is that slant from texture is based on an inaccurate optical variable. An alternative Bayesian explanation is that perceptual underestimation is due to the influence of frontal cues and/or a frontal prior, which is weighted according to the reliability of slant cues. We measured slant perception using a hand-alignment task for conditions that provided only texture, only stereo, or combined texture and stereo cues. Slant estimates from monocular texture showed large biases toward frontal, with proportionally more underestimation at low slants than high slants. Slant estimates from stereo alone were more accurate, and adding texture information did not reduce accuracy. These results are consistent with a frontal influence that is decreasingly weighted as slant information becomes more reliable. We also included conditions with small cue conflicts to measure the relative weighting of texture and stereo cues. Consistent with previous studies, texture had a significant effect on slant estimates in binocular conditions, and the relative weighting of texture increased with slant. In some cases, perceived slant from combined stereo and texture cues was higher than from either cue in isolation. Both the perceptual biases and the cue weights were generally consistent with a Bayesian model that optimally integrates texture and stereo slant cues with frontal cues and/or a frontal prior.

Object-centered reference frames in depth as revealed by induced motion.

An object-centric reference frame is a spatial representation in which objects or their parts are coded relative to others. The existence of object-centric representations is supported by the phenomenon of induced motion, in which the motion of an inducer frame in a particular direction induces motion in the opposite direction in a target dot. We report on an experiment made with an induced motion display where a degree of slant is imparted to the inducer frame using either perspective or binocular disparity depth cues. Critically, the inducer frame oscillates perpendicularly to the line of sight, rather than moving in depth. Participants matched the perceived induced motion of the target dot in depth using a 3D rotatable rod. Although the frame did not move in depth, we found that subjects perceived the dot as moving in depth, either along the slanted frame or against it, when depth was given by perspective and disparity, respectively. The presence of induced motion is thus not only due to the competition among populations of planar motion filters, but rather incorporates 3D scene constraints. We also discuss this finding in the context of the uncertainty related to various depth cues, and to the locality of representation of reference frames.

International Nurses Day and press coverage in South Africa.

BACKGROUND: In some countries, nursing's appeal as a profession is diminishing, partly due to poor press coverage and the media's portrayal of an over-loaded, poorly paid profession. The media is important for shaping public perceptions and raising policy issues. International Nurses Day gives nurses an opportunity to profile their critical contribution to quality health care. AIM: To determine the influence of this commemorative day on press coverage about nursing by examining whether there was a difference in the proportion of South African press articles on nursing between January-April and May-June 2010. METHODS: A quantitative content analysis was conducted of all press articles mentioning 'nursing' or 'nurse/s' in the South African lay press from 1 January-31 June 2010. Articles were coded for theme, slant and prominence, and inter-coder reliability was assessed. Descriptive statistics with chi square or Fisher's exact tests were used to compare the two time periods. RESULTS: We identified 242 articles in 95 publications. The month of May had almost double the press coverage of January. International Nurses Day articles were mainly positive, and appeared in May to June in weekly community publications rather than in daily national and regional newspapers. When they were excluded, most articles portrayed nursing negatively. LIMITATIONS: The 6-month period may not be representative of the entire year. Only the dominant topic was coded, which possibly influenced the analysis. CONCLUSION: International Nurses Day positively influenced the extent and slant of press coverage. Efforts to sustain coverage beyond the event through strategic partnerships and media engagement should be strengthened. IMPLICATIONS FOR NURSING AND HEALTH POLICY: The media's portrayal of nurses and nursing may influence the choice of nursing as a career. International Nurses Day is an opportunity to portray nursing positively. Media training may help nurses to advocate for their profession in the media.

Depth compression based on mis-scaling of binocular disparity may contribute to angular expansion in perceived optical slant.

Three studies, involving a total of 145 observers examined quantitative theories of the overestimation of perceived optical slant. The first two studies investigated the depth/width anisotropies on positive and negative slant in both pitch and yaw at 2 and 8 m using calibrated immersive virtual environments. Observers made judgments of the relative lengths of extents that were frontal with those that were in depth. The physical aspect ratio that was perceived as 1:1 was determined for each slant. The observed anisotropies can be modeled by assuming overestimation in perceived slant. Three one-parameter slant perception models (angular expansion, affine depth compression caused by mis-scaling of binocular disparity, and intrinsic bias) were compared. The angular expansion and the affine depth compression models provided significantly better fits to the aspect ratio data than the intrinsic bias model did. The affine model required depth compression at the 2 m distance; however, that was much more than the depth compression measured directly in the third study using the same apparatus. The present results suggest that depth compression based on mis-scaling of binocular disparity may contribute to slant overestimation, especially as viewing distance increases, but also suggest that a functional rather than mechanistic account may be more appropriate for explaining biases in perceived slant in near space.